condemned.’ The 1970 Declaration on Friendly Relations (Resolution 2625) followed the same approach. It spelled out the content of the prohibition of the use of force as regards civil conflict: ‘Every state has the duty to refrain from organizing, instigating, assisting or participating in acts of civil strife or terrorist acts in another State or acquiescing in organized activities within its territory directed towards the commission of such acts, when the acts referred to in the present paragraph involve a threat or use of force.’ The duty of non-intervention added to this the duty not to foment, finance, incite or tolerate subversive, terrorist or armed activities directed towards the violent overthrow of the regime of another state and the duty not to interfere in civil strife in another state.
The International Court of Justice in the Nicaragua case and in Armed Activities on the Territory of Congo confirmed that these provisions of the Declaration on Friendly Relations were declaratory of customary international law.4 Thus, the status of the rules on forcible intervention in civil wars is not controversial; it was their application that led to fundamental divisions during the Cold War when the superpowers and others waged proxy wars in Africa, Latin America, and Asia. The previous chapter centred on the debate as to the proper interpretation of Article 2(4); this chapter will show that in the vast majority of cases of forcible intervention in a civil war it is not the interpretation but the application of the law that leads to difficulty. That is, there is a general consensus between states as to the principles to be applied to forcible intervention in civil conflicts, but in practice the disagreements as to the facts and as to the application of the law to those facts can fundamentally divide states, as can be seen clearly in the accusations and counter-accusations between Chad and Sudan; the DRC, Rwanda and Uganda; Ethiopia, Eritrea and Somalia; the USA, Iran and Syria; Pakistan and Afghanistan; Georgia and Russia.
The conflict which started in the vast, mineral-rich Democratic Republic of Congo (DRC, formerly Zaire) in 1998 serves as an example, though perhaps an unusually complex example, illustrating the type of conflict that has been common since the Second World War.5 After thirty-two years in power President Mobutu, supported by France throughout the Cold War, was overthrown by Laurent Kabila in May 1997 with the help of forces from some of the nine neighbouring states. Uganda and Rwanda helped Kabila to seize power partly because they were concerned to stop insurgents operating from the territory of the DRC challenging their governments. But when President Kabila came to power he himself used these insurgent forces and was seen as betraying his former allies; Uganda and Rwanda turned against him and undertook extensive military activities on the territory of the DCR against the government, against rebel groups and even against each other.6 President Kabila sought help from Zimbabwe, Namibia, and Angola and they sent forces to support him in August 1998. They were apparently motivated in part by hostility to ex-President Mobutu; he had for many years supported UNITA opposition forces which had operated against their governments. Mobutu had continued to back UNITA even after the USA and South Africa had abandoned it. Congo (Brazzaville), Central African Republic, Sudan, Chad, and Gabon also promised help to Kabila. Thus a civil conflict in the DRC was fuelled by outside involvement from many states because conflicts in their states had spilled over into the DRC and because the DRC had played a role in the conflicts in other states.7 This conflict gave rise to the Case concerning Armed Activities on the Territory of the Congo (DRC v Uganda) before the ICJ.8
The Security Council, in Resolution 1234 (1999), expressed its concern at the continuation of hostilities and stressed its firm commitment to preserving the national sovereignty, territorial integrity, and political independence of the DRC. In particular it was concerned at reports of measures by forces opposing the government of President Kabila in violation of the national sovereignty and territorial integrity of the country; in the preamble it recalled the inherent right of individual or collective self-defence in accordance with Article 51 of the UN Charter. It also deplored the continuing fighting and the presence of foreign troops in a manner inconsistent with the principles of the Charter of the UN and called upon those states to bring to an end the presence of the uninvited forces.
This resolution is stronger than the earlier reaction of the Security Council when President Mobutu was overthrown by Laurent Kabila with the help of Rwanda and Uganda in 1997; the Security Council then simply expressed concern at the deteriorating situation in the region and called on the revolutionary forces led by Kabila to accept an immediate cessation of hostilities and the implementation of a peace plan.9 The Security Council subsequently expressed its support for the people of the DRC as they began a new period in their history. However, it also rejected outside intervention. It said that the Council respected the legitimate national aspirations of the people of the DRC to achieve peace, national reconciliation and progress in the political, economic, and social fields to the benefit of all, and opposed any interference in its internal affairs. It called for the withdrawal of all external forces.10
Resolution 1234(1999) clearly reflects the duty not to use force against another state and also the duty not to intervene in its internal affairs. It is based on the legal right of the government of the DRC to seek help and the illegality of the behaviour of the foreign states using force to overthrow that government. It shows that the Security Council regarded the conflict as a mixture of civil war and inter-state conflict and that it took a clear position: aid to the government was permissible, intervention or force to overthrow the government was not.
However, the Security Council subsequently took a more ambiguous position as the war continued. After the Lusaka Ceasefire Agreement between the DRC and the five regional states involved in the conflict was concluded in July 1999 the Security Council’s main concern was to secure implementation of that Agreement and the deployment of a peacekeeping force, MONUC.11 The government of Laurent Kabila proved reluctant to cooperate with the peace process.12 The Security Council accordingly stressed the mutual obligations of all the states under the Lusaka Ceasefire Agreement, and the duty of all foreign forces to withdraw from the DRC; it did not again refer to the rights of individual and collective self-defence.13 The DRC repeatedly wrote to the Security Council objecting that it was necessary to distinguish between the aggressor states—Uganda and Rwanda—and those aiding the legitimate government.14 Rwanda and Uganda continued to maintain that they had no territorial interests or economic interests in the DRC, but that they were concerned only to protect themselves against rebel forces operating from the DRC.15 However, there were armed clashes between the forces of Rwanda and Uganda in Kisangani in August 1999.16 And the Expert Panel created by the Security Council to report on the ‘Illegal Exploitation of Natural Resources of the DRC’ reported that the armies of Uganda and Rwanda had carried out, first, mass-scale looting and then systematic exploitation of the DRC’s rich mineral resources.17
The Security Council started to distinguish between invited and uninvited forces again after the events of June 2000, when Ugandan and Rwandan forces fought over the diamond trade centred on the town of Kisangani—the first time since the Second World War that two foreign regular armies had engaged with each other in the territory of a third state with a view to appropriating that state’s wealth.18 The Security Council used unusually strong language in Resolution 1304 (2000). In the preamble it expressed its ‘outrage at renewed fighting between Ugandan and Rwandan forces in Kisangani’. It unreservedly condemned the fighting and expressly demanded that Uganda and Rwanda ‘as well as forces of the Congolese armed opposition and other armed groups’ withdraw their forces from Kisangani. It demanded that Uganda and Rwanda ‘which had violated the sovereignty and territorial integrity of the DRC’ withdraw all their forces from its territory without delay, in conformity with the timetable of the Ceasefire Agreement. In its subsequent resolutions, although it called for the withdrawal of all foreign forces, the Security Council continued expressly to single out Uganda and Rwanda.19 It did, however, also address the security concerns of Rwanda with regard to opposition forces operating from the DRC20 and condemn incursions into Rwanda and Burundi by armed bands from the DRC.21
After Laurent Kabila was assassinated in January 2001 he was succeeded as President by his son, Joseph Kabila, who was more willing to participate in the peace-making process.22 Bilateral peace agreements between the DRC and Uganda and Rwanda in 2002 led finally to major withdrawals of troops.23 The states assisting the government of the DRC also began to pull out their troops.24 A final peace agreement was reached at the end of 2002 and a new government was installed.25 But the government found it difficult to assert control over its vast territory and fighting between armed militias continued, especially in the east of the country, despite the deployment of a large UN force in 2003. In 2004 the DRC accused Rwanda of continued intervention and requested the Security Council to impose sanctions on it.26 The Security Council took a cautious approach and in its resolutions it urged not only Rwanda but also Burundi, Uganda and the DRC to ensure that their territory was not used in support of activities of armed groups or to infringe the sovereignty of others.27 At the end of 2004 when Rwanda openly threatened to send its armed forces back into the DRC to take action against Rwandan rebel forces operating from the DRC, the Security Council went slightly further: in a statement it expressed very deep concern at the multiple reports of military operations by the Rwandan army in the eastern part of the DRC; underlined that the threat or use of force was contrary to the UN Charter; strongly condemned any such military action; and demanded that Rwanda withdraw without delay any troops it may have on the territory of the DRC.28 Although this stopped short of any formal finding of unlawful intervention by Rwanda it clearly comes near to such a finding.
The situation in eastern DRC gradually improved, but there was still intermittent fighting between militias. In 2005 the Secretary-General said that it was difficult to assess whether direct support to the militia groups in Ituri was being provided from neighbouring countries, but reports indicated that representatives of the groups moved freely between the DRC, Uganda and Rwanda. He urged neighbouring states to ensure that remaining militia groups were not allowed to use their territories as rear bases, safe havens or as a supply route for illegal arms trafficking.29 There were still tensions between the DRC and Uganda because of the operation of the Ugandan rebels, the Lord’s Resistance Army, on the territory of the DRC.30 There were also incursions on the border with Burundi,31 and continuing problems with Rwanda.32 Relations between the states of the region nevertheless improved and the signing of the Pact on Security, Stability and Development in the Great Lakes Region by eleven regional states on 15 December 2006 was an ‘historic development’ bringing hope for the future.33 This Pact includes a Protocol on Non-aggression a nd Mutual Defence in which the parties undertake ‘to abstain from sending or supporting armed opposition forces or armed groups or insurgents onto the territory of other states or from tolerating the presence on their territories of armed groups or insurgents engaged in armed conflicts or involved in acts of violence or subversion against the Government of another state’.
However, the security situation in the east deteriorated in 2007, and serious fighting between dissident militias and government forces broke out.34 The Security Council expressed its grave concern at the continued presence of foreign armed groups in the east. It commended the joint efforts of the DRC and Rwanda to address their common security concerns through dialogue and cooperation and welcomed their November 2007 agreement on a common approach to end the threat posed to peace and stability to both countries.35
Just as the Security Council with regard to the conflict in the DRC drew a distinction between outside forces invited by the government and those of Uganda and Rwanda, so with regard to other conflicts the Security Council has taken the same approach. When civil war broke out in Congo (Brazzaville) in 1997, Angola intervened and sent troops to support the opposition forces, which then secured victory. The Security Council, in a Presidential Statement, condemned outside intervention; it expressed concern about the grave situation and called for an end to hostilities. It condemned all external interference, including the intervention of foreign forces, in violation of the Charter of the UN and called for the immediate withdrawal of all foreign forces.36
The traditional position was again adopted with regard to intervention in the conflict in Sierra Leone. A civil war started in 1991 when opposition forces of the Revolutionary United Front (RUF) tried to overthrow the government. The RUF refused to accept the settlement ending the conflict and did not participate in the 1996 elections. It seized power in a military coup in 1997, but the UN refused to accept the overthrow of the democratically elected government under President Kabbah and this government was restored in 1998. The RUF continued their armed struggle. There were accusations that President Charles Taylor of Liberia was intervening to assist them to overthrow the government of Sierra Leone.37 Many states in West Africa, including Sierra Leone, Liberia, Guinea and Côte d’Ivoire, were involved in a series of interconnected conflicts.38 Armed elements and criminal gangs operated across the borders; massive refugee flows aggravated the situation; the states in the region made accusations and counter-accusations of unlawful intervention.39 The Security Council called on all states in the region to take action to prevent armed groups from using their territory to prepare and commit attacks on neighbouring countries, but it singled out Liberia for express condemnation and sanctions. In Resolution 1343 (2001) it demanded that the government of Liberia immediately cease its support for the RUF in Sierra Leone and for other armed rebel groups in the region; called on it to expel RUF members from Liberia and to prohibit all RUF activities on its territory; to cease all financial and military support to the RUF, including all transfers of arms and all military training; and it imposed measures under Article 41 on Liberia and individual members of its government.40 Later it called on Liberian forces to refrain from unlawful incursions into Sierra Leone, and expressly determined that the active support by the Government of Liberia to armed rebel groups in the region, including to rebels in Côte d’Ivoire and former RUF combatants who continued to destabilize the region, constituted a threat to international peace and security in the region.41
The Security Council reaction to these interventions in civil conflict constitutes a clear reaffirmation of the prohibition of forcible intervention.42 Resolution 1234 on the DRC used the language both of Article 2(4) and of the rules on intervention. This and the other statements of the applicable rules by the Security Council reflect the reasoning of the Court in the Nicaragua case, of paramount importance in this area. The Court has recently reaffirmed its commitment to this approach in the Case Concerning Armed Activities on the Territory of Congo (DRC v Uganda).
This case was brought by Nicaragua against the USA both for the unlawful use of force against the government of Nicaragua and for its intervention through its support for military and paramilitary activities of the opposition contra forces. The part of the judgment which deals with the use of force and non-intervention provides an authoritative statement of the law on this area; it has proved relatively uncontroversial among commentators, in contrast to the critical response from many US writers to the Court’s reasoning on collective self-defence.44 Indeed, there was consensus between the USA and Nicaragua as to the applicable law.45
Issues of classification played a central role in this case. Did the actions of the USA constitute an illegal use of force against Nicaragua under the customary international law rule codified in Article 2(4)? Were its actions an unlawful intervention against the government of Nicaragua? If so, could they be justified as collective self-defence or collective countermeasures in protection of Costa Rica, Honduras and El Salvador against an armed attack or unlawful intervention by Nicaragua?46 The Court undertook an examination of the prohibition of intervention and of the scope of the prohibition of the use of force; it elaborated on the content of these two sets of rules and on the relationship between them. As regards the identification of the customary law on the prohibition of the use of force codified in Article 2(4), the Court used the Declaration on Friendly Relations principles on the use of force quoted at the start of this chapter on the duty not to organize civil strife in another state in support of an opposition party.47 It also set out the basic law on intervention at some length: ‘The principle of non-intervention involves the right of every sovereign state to conduct its affairs without outside interference; though examples of trespass against this principle are not infrequent, the Court considers that it is part and parcel of customary international law.’ 48 It invoked the Corfu Channel case, General Assembly resolutions and inter-American practice as authority for the principle of non-intervention.
The Court then went on to consider the exact content of the principle as far as was relevant to the resolution of the dispute:
The principle forbids all states or groups of states to intervene directly or indirectly in internal or external affairs of other states. A prohibited intervention must accordingly be one bearing on matters in which each state is permitted, by the principle of state sovereignty, to decide freely. One of these is the choice of a political, economic, social and cultural system, and the formulation of foreign policy. Intervention is wrongful when it uses methods of coercion in regard to such choices, which must remain free ones. The element of coercion, which defines, and indeed forms the very essence of, prohibited intervention, is particularly obvious in the case of an intervention which uses force, whether in the direct form of military action, or in the indirect form of support for subversive or terrorist armed activities within another state. General Assembly resolution 2625 (XXV) equates assistance of this kind with the use of force by the assisting state when the acts committed in another state involve a threat or use of force. These forms of action are therefore wrongful in the light of both the principle of the non-use of force and that of non-intervention.49
The Nicaragua case thus made clear the considerable overlap between the rules on forcible intervention and the customary law codified in Article 2(4).
After its statement of the general prohibition of forcible intervention the Court had to consider whether any fundamental modification of the principle of non-intervention had taken place. Significantly, the USA did not itself put forward any argument that there had been such a fundamental shift in the law. It did not advance the argument that it had a legal right to help the opposition contras to use force to overthrow a government; it based its right to use force on collective self-defence. Nevertheless, the Court examined the possible argument that the USA was justified in using force against Nicaragua to help the contras in their forcible opposition to the government. The International Court of Justice said that a government may invite outside help, but a third state may not forcibly help the opposition to overthrow the government. Although there had been in recent years a number of instances of foreign intervention for the benefit of forces opposed to the government of another state this did not in itself change the law. The Court had to consider whether there were indications of a practice illustrative of a belief in a kind of general right for states to intervene in support of internal opposition in another state, whose cause appeared particularly worthy by reason of the political and moral values with which it was identified. For such a general right to come into existence, a fundamental modification of the customary principle of non-intervention would be involved.
The Court, in considering whether there was opinio juris to support such a change, said it had to take account of the grounds offered by states to justify their interventions in support of opposition; states had not in fact justified their conduct by reference to a new right of intervention or a new exception to the principle of its prohibition. The United States authorities had on some occasions stated their grounds for intervening in the affairs of a foreign state for reasons connected with the domestic policies of that country or its ideology, the level of its armaments or the direction of its foreign policy. But these were statements of international policy and not an assertion of rules of existing international law. Accordingly, ‘The Court therefore finds that no such general right of intervention in support of an opposition within another State exists in contemporary international law. The Court concludes that acts constituting a breach of the customary principle of non-intervention will also, if they directly or indirectly involve the use of force, constitute a breach of the principle of non-use of force in international relations.’50 It later said that the principle of non-intervention would certainly lose its effectiveness as a principle of law if intervention ‘which is already allowable at the request of the government of a State’ were also to be allowed at the request of the opposition. This would permit any state to intervene at any moment in the internal affairs of another state.51
On the facts of the case the Court found that the US aid to the contras in Nicaragua in ‘recruiting, training, arming, equipping, financing, supplying and otherwise encouraging, supporting, aiding and directing military and paramilitary actions in and against Nicaragua’ was a breach of the prohibition of the use of force. The Court found that the USA had committed a prima facie violation of the principle of the non-use of force by ‘organizing or encouraging the organization of irregular forces or armed bands . . . for incursion into the territory of another state’ and ‘participating in acts of civil strife in another state’ in the terms of the Declaration on Friendly Relations. The arming and training of the contras could be said to involve the threat or use of force against Nicaragua, but the mere supply of funds to the contras, while undoubtedly an act of intervention in the internal affairs of Nicaragua, did not in itself amount to a use of force.52
The Court made it clear that it was not necessary to show that the intent behind the US intervention was actually to overthrow the government of Nicaragua. Nicaragua had claimed that this was the aim of the USA. But the Court said that in international law, if one state, with a view to the coercion of another state, supports and assists armed bands in that state whose purpose is to overthrow the government, that amounts to an intervention, whether or not the political objective of the state giving such support and assistance is equally far-reaching.53
In 2005 the Court followed the Nicaragua case in its judgment on the case brought by the DRC against Uganda. The DRC in its Application accused Uganda of aggression, and of violation of the principle of unlawful use of force and also of ‘the principle of non-interference in matters within the domestic jurisdiction of states which includes refraining from extending any assistance to the parties to a civil war operating on the territory of another state’. Uganda admitted its assistance to an armed opposition group, the MLC, but claimed that this was limited to what was justified in self-defence.55 Like the USA in the Nicaragua case, Uganda did not claim a right to support armed opposition groups in their military campaign to overthrow a government, but rather a right to self-defence. It said that it was not acting unlawfully in supporting the armed opposition groups as it had refrained from providing the rebels with the kind or amount of support they would have required to achieve such far-reaching purposes as the conquest of territory or the overthrow of the Congolese government.56
The Court confirmed that the provisions of the 1970 Declaration on Friendly Relations on non-intervention were declaratory of customary international law.57 It held that Uganda’s actions were not justified self-defence,58 and since Uganda had admitted its training and military support for the MLC it was guilty of unlawful intervention. As in the Nicaragua case, Uganda could be held to have violated the prohibition on intervention even if its objective was not actually to overthrow President Kabila.59 ‘The Court accordingly concludes that Uganda has violated the sovereignty and also the territorial integrity of the DRC. Uganda’s actions equally constituted an interference in the internal affairs of the DRC and in the civil war there raging. The unlawful military intervention by Uganda was of such a magnitude and duration that the Court considers it to be a grave violation of the prohibition on the use of force expressed in Article 2, paragraph 4, of the Charter.’60
The Court considered another aspect of the law on intervention in regard to Uganda’s first Counterclaim against the DRC.61 Uganda claimed that the DRC had violated the principles of non-use of force and non-intervention because it had not only actively supported anti-Ugandan rebels operating from the DRC against the government of Uganda, but had also tolerated the activities of the rebels on its territory. This argument invokes a different aspect of the duty of non-intervention from that alleged by the DRC, and from that involved in the Nicaragua case. Uganda said that the duty of non-intervention involved not only the duty not to provide support to groups carrying out subversive or terrorist activities against another state, but also a ‘duty of vigilance’ to ensure that such activities were not tolerated. It argued that the DRC was guilty of intervention not only because of its active support for the anti-Ugandan rebels, but also because it had tolerated their activities on the territory of the DRC. According to the decision of the Court in the Corfu Channel case, every state had an obligation not to allow knowingly its territory to be used for acts contrary to the rights of other states.
The Court accepted that the prohibition of intervention as set out in the Declaration on Friendly Relations includes a ‘duty of vigilance’: the Declaration provides that ‘every State has the duty to refrain from . . . acquiescing in organized activities within its territory directed towards the commission of such acts’ (e.g., terrorist acts, acts of internal strife) and also that ‘no State shall . . . tolerate subversive, terrorist or armed activities directed towards the violent overthrow of the regime of another State’. However, Uganda failed to prove its allegations of intervention. It did not show active support by the DRC for attacks on Ugandan territory.62 Nor did it show acquiescence or toleration of anti-Ugandan rebels on its territory. The parties did not dispute the presence of the rebels on the territory of the DRC. Uganda argued that before 1997 the rebel groups were able to act unimpeded in the border region because of its mountainous terrain, its remoteness from the capital and the almost complete absence of central governmental presence in the region. The Court did not accept that the absence of action by the government of the DRC (then known as Zaire) against the rebel groups in the border area was tantamount to ‘tolerating’ or ‘acquiescing’ in their activities.63 At first the DRC had not been capable of stopping the actions of the rebels; subsequently it had in fact taken clear action.64 This is an important decision on the scope of the duty of non-intervention. The Court took a strict approach and was not willing to accept that inability to act against rebels or ineffective action make a state guilty of intervention. There must be actual toleration or acquiescence.65 Clearly this may be difficult to prove. Hence the dissenting judges in this case argued it was for the state accused of unlawful intervention to show that it had discharged its ‘duty of vigilance’, but the Court did not agree.66 The practical difficulties in proving violation of this duty may be seen arising from the accusations and counter-accusations of the governments of Afghanistan and Pakistan, each accusing the other of toleration of Taliban and Al Qaeda forces operating from their territories in 2006–7.67
The reference by the Court in the Nicaragua case to the legality of intervention in response to an invitation by the government was very brief; this brevity masks the complexity that may arise in the interpretation and application of this rule. The basic principle of the right of a government to invite a third state to use force and the absence of any such right for an opposition may be accepted in theory, but its application in practice has not been simple.68 The previous chapter examined the debates as to humanitarian intervention, national liberation movements, and pro-democratic intervention; the law on all these may affect the legality of help to the opposition in a state. Various other limits on the right of a government to seek and receive outside assistance have been suggested as evolving through practice since the inception of the UN. The duty of non-intervention and the inalienable right of every state to choose its political, economic, social, and cultural systems have brought with them the duty not to intervene to help a government in a civil war. However, if there has been outside subversion against the government, then help to the government becomes permissible, whether or not there is a pre-existing treaty provision for this. And if the conflict is limited then it will not be characterised as a civil war, but merely as domestic unrest, and so help will be permissible.
This generally agreed position was put forward by the UK in a Foreign Policy Document in 1984 which set out the general prohibition of forcible intervention and the possible exceptions to this.69 It said that normally if one state requested assistance from another, then clearly that intervention could not be dictatorial and therefore unlawful. But a major restriction on the lawfulness of states providing outside assistance to other states was that any form of interference or assistance was prohibited when a civil war was taking place and control of the state’s territory was divided between warring parties.70 However, it was widely accepted that outside interference in favour of one party to the struggle permitted counter-intervention on behalf of the other.71
The categorization of a conflict may therefore be crucial in the determination of the legality of forcible intervention. The question arises first as to whether a conflict is actually a civil war or whether it is merely limited local unrest. Are opposition forces in control of territory? This line between unrest and civil war has proved controversial. States have not on the whole been willing to admit that the threshold of a civil war has been reached; they see such an acknowledgement as legitimating opposition forces. This has proved a fundamental obstacle to the effective implementation of humanitarian law in non-international armed conflicts. Second, if the conflict is a civil war, is it a purely civil war or has there been outside intervention? What has been the scope of the outside intervention: does it amount to an armed attack allowing collective self-defence or is it merely a lesser intervention allowing aid short of collective self-defence to the government? Is the government using force against a people with the right of self-determination? All these issues affect the rights of third states to intervene to assist the government.
Even the determination as to whether a conflict is an inter-state conflict or a civil war may be far from straightforward. Questions as to classification—is the conflict civil or international?—may be decisive as to the applicable law and as to the legality of the use of force. In the past this issue came up dramatically over the 1961–75 war in Vietnam. The competing parties fundamentally disagreed as to the nature of the conflict. The USA and South Vietnam argued that the conflict was an inter-state war begun by the invasion of South Vietnam by North Vietnam, a Cold War conflict in which the USA was operating in collective self-defence of its ally against a Chinese-aided invasion by North Vietnam, and later also against forces in Cambodia and Laos. North Vietnam argued that the conflict was one of decolonization; the people of the whole of Vietnam were resisting the perpetuation of colonial rule.72 If the former was accurate, then the rules applicable were those in Article 51 on inter-state conflict; if the latter view was correct, then the conflict was one in which the USA was intervening in a struggle for decolonization by the people of the whole of Vietnam. The Security Council did not play an active role in this conflict and did not pronounce on the issue.73 Conflicts in other divided states such as Korea, Yemen, and Ireland have given rise to similar issues of classification.
More recently the question of classification came up in the 1991–95 conflict in Bosnia-Herzegovina.74