Definition and General Rules As defined by international lawyers, intervention is unsolicited interference by one state in the affairs of another; nonintervention is the avoidance of such interference. Intervention may be directed against a single state or factions within it, or it may involve interference with the interactions among a group of states. It may take the form of military action or economic or political pressures. These pressures force states to act in a manner prescribed or foreordained by the intervening state. Alternatively, the intervening state may use its own agents to carry out the policies that it desires. States yield because they fear military coercion or nonmilitary punitive actions or because they cannot stop the intervening state's agents or activities.
Although the elements of intervention can be readily outlined, they are hard to identify in specific political situations. Most relations among states contain elements of coercion whenever interacting parties feel constrained to make some concessions to each others' wishes. It is difficult to determine at what point pressure becomes coercive enough to be considered an intervention because consent was unwilling and therefore deemed void. For instance, when a country desperately needs economic aid from the United States or international agencies whose policies the U.S. controls, is it intervention to make aid contingent on privatizing that country's banking system? Normal intercourse among states merges almost imperceptibly into interventionist practices. In a community of nations that is comprised of states of varying powers and degrees of interdependence, nations lacking in economic and political resources are most likely to experience interventionist pressures. The world community has not yet agreed on the borderline between the right of the stronger power to insist on its terms, and the right of the weaker power to conduct its affairs free from coercion. At the other end of the spectrum of coercion, it has at times been difficult to determine when interventions become outright warfare.
A second problem arises from the interdependence of nations in the community of nations, which makes the complete independence envisaged by the concept of sovereignty a legal fiction, rather than a viable reality. In a community of interdependent nations, the domestic or foreign policies of state A frequently have a direct effect on the affairs of state B. When the United States closes its borders to Mexican farm laborers hired for seasonal work in the United States, the Mexican economy suffers. There is disagreement about whether intervention has taken place when the actions of A—and even inactions—seriously affect B but have not been primarily designed to affect B. If, as many international lawyers contend, intent to intervene is essential to establish the fact of intervention, the difficulty of proving intent seriously impedes accurate findings. For instance, the United States stopped the exportation of scrap metal to Japan prior to World War II, giving U.S. national defense needs as the reason. Japan claimed that the measure was intended to force a change in its military policies. It was difficult to prove at the time which claim was correct.
A third problem is tied to the question of responsibility of a state for the actions of its nationals. Citizens of country A, enraged about the treatment of religious minorities, revolutionaries, or foreign business establishments in country B, may openly or covertly interfere in the politics of country B to change policies that they think are offensive. It remains unsettled whether and under what circumstances their government becomes implicated by their activities. For example, Americans who were outraged by the racial policies of a South African government controlled by whites who were an ethnic minority pressured various American enterprises in the 1980s and 1990s to withdraw their investments from South Africa unless racial policies were changed. The withdrawals caused major economic dislocations and contributed to the ultimate fall of the minority government.
The problem of accurate identification of interventionist actions was of minor significance in the eighteenth and nineteenth centuries, because most interventions by the major European powers in the affairs of weak states were then deemed permissible self-defense actions under international law. In fact, rulers in Europe considered intervention a moral duty to uphold their common culture and to protect the political status quo. When the status quo was threatened by the French Revolution, the major European powers pledged support of interventions that would uphold the existing balance of power and maintain established governments.
Numerous interventions took place for these causes. For example, Prussia, Austria, and Russia intervened in Spain, Naples, and Piedmont in 1820 to suppress revolution against the established governments. Similarly, from 1827 to 1832, during the Greek war of independence, Britain, France, and Russia repeatedly intervened in the internal affairs of Greece and Turkey to maintain the balance of power in the Middle East. Other interventions were designed to protect religious groups and minorities, especially when they had ties to the intervening country. Despite high regard for the principle of state sovereignty, international law and practice in the nineteenth century sanctioned a broad right of intervention to protect the interests of nations strong enough to exercise this right to maintain the political status quo.
In the twentieth century, international developments changed the concept of unquestioned legality of all interventions, raising the problem of defining the nature of legal and illegal interventions. The decline of autocratic monarchies and the rise of democratically controlled nations in the wake of the French Revolution had weakened the idea of a community of nations jointly responsible for preserving the existing political landscape. Democratic and autocratic governments had little in common except the reciprocal fear that one was determined to destroy the other. They did not share the sense of kinship and personal moral obligation that had united the crowned heads of Europe. Nor did they agree about the most advantageous policies for Europe and the aims worthy of individual or collective intervention.
Fearing each other, European states wanted to make sure that they would be able to conduct their affairs unhindered by other nations. They therefore looked to the theory of state sovereignty and to claims of an inherent freedom of self-determination as foundations for legal restraints that would protect them from unbridled interventionism by other members of the international community. Gradually, the efforts of small nations, supported by larger countries opposed to interventions to sustain absolute governments in Europe, undermined the concept of an unlimited right of intervention. The notion of a duty of intervention to prevent politically harmful changes was replaced by the concept of a duty of nonintervention subject only to a small number of exceptions.
By the middle of the twentieth century, changing legal philosophies, buttressed by a number of specific resolutions and multilateral treaties, including the Montevideo Convention on the Rights and Duties of States (1933) and the United Nations Charter (1945), had made it a general rule of international law that states may not interfere in matters customarily deemed to be the exclusive purview of another state. A state's internal affairs and its relations with third parties are inviolable. Article 2, paragraph 7 of the UN Charter states that "Nothing contained in the present Charter shall authorize the United Nations to intervene in matters which are essentially within the domestic jurisdiction of any state."
While nonintervention is the general rule, it is still limited by a right of intervention in cases where the current or imminent actions of one state endanger vital concerns of another state or of the community of nations. The clamor of small states for a total prohibition of all interventions has never been heeded. Accordingly, Article 2, paragraph 7 of the charter also provides that the nonintervention principle "shall not prejudice the application of enforcement measures under Chapter VII." Under Chapter VII, states retain the right of coercive action, including the use of military force, to protect international peace and security.
In fact, there has been a partial swing back to the notion that intervention may be a duty to assure the right of people everywhere to be governed democratically and to be protected from violations of their basic rights as human beings. The Universal Declaration of Human Rights, adopted by the United Nations General Assembly in 1948, laid out the scope of these rights. They include bans on genocide and war crimes. The declaration urges member nations to secure "universal and effective recognition and observance" of these rights. Subsequently, the 1951 Convention on the Prevention and Punishment of the Crime of Genocide spelled out in detail that actions such as killing members of national, ethnic, racial, or religious groups, or harming them bodily or mentally, or preventing them from having children, constitutes genocide. The Nuremberg Tribunal, set up to try German war criminals after World War II, established the principle that political leaders and their minions are personally responsible for atrocities they commit as part of their official duties. In the 1990s, international criminal tribunals were set up to try individuals accused of crimes against humanity in Rwanda and the former Yugoslavia. The activities of these tribunals demonstrate that individual responsibility for crimes against humanity can be enforced to some degree under existing international laws. The 1998 Rome Statute for creating an International Criminal Court, which was signed by 120 countries within two years of its adoption, is further evidence that the world community concurs that human rights should be protected under international law.
In 1999, United Nations Secretary-General Kofi Annan urged UN members to devise and pursue more effective policies to stop egregious human rights violations. He acknowledged that some nations might oppose humanitarian interventions as violations of state sovereignty. He countered this contention by arguing that the moral duty of the world community to stop human rights violations trumped an offending state's rights to sovereignty. In line with such widespread sentiments, which nonetheless lack the force of law, the United States has been criticized by political leaders at home and abroad for neglecting its "duty" to prevent or stop genocide, irrespective of its own interests. The issue arose in the Balkans, in Uganda, and in Indonesia when civil strife led to "ethnic cleansing" policies because ruling factions in these states or regions committed atrocities designed to kill or otherwise eliminate undesired minorities from their lands.
Application Problems The general rule that states may intervene in the affairs of other states to protect their own vital interests has been difficult to apply because there is no agreement on the definition of "vital interests." Are the interests that may be protected limited to matters of military security, or do they include major economic and social stakes? Must the danger be imminent or is there a right of preventive intervention? Is it a vital right to protect the property of one's citizens from physical harm in states where effective government has collapsed? Who determines that vital interests are endangered and that intervention is needed to protect them? What is an equitable balance between the safeguarding of vital interests of the intervening state and those of the state subject to intervention? If a state violates the human or political rights of individuals within its borders, or if its actions endanger international peace, do members of the international community have the duty to interfere to enforce the norms of the international community? May they intervene on behalf of established governments under attack by revolutionary forces within their own borders? The answers to these questions remain highly controversial.
These problems are further clouded by vociferous statements of political activists who invoke moral and ethical norms. They claim that interventions on behalf of "good" causes, as they define them, are legal and a moral duty, while interventions for "bad" causes are illegal, unethical, and immoral. Good causes range from aiding persecuted individuals to the duty to provide peoples with good governments to the obligation to stop civil wars or bring about the victory of the allegedly more virtuous side.
A second area of controversy concerns the means of intervention. There is substantial consensus that illegal intervention has occurred when a state dispatches armed forces to the territory of another. The Covenant of the League of Nations (1918), the Kellogg-Briand Pact (1928), and the United Nations Charter (1945) are examples of international agreements outlawing such armed interventions. There is far less agreement about the legality of the vast array of nonmilitary pressures by which states can affect the affairs of other states. These include economic pressures, such as an offer or withdrawal of loans, trade, or aid, including military supplies; political pressures, such as granting recognition to an acceptable government to bolster its power, and withholding of recognition from an unacceptable government in hopes of toppling it; and psychological pressures, such as expressing support for one side in a revolution, denouncing the policies of another state, or excluding it from international meetings. There is a good deal of disagreement about which of such economic, political, and psychological pressures are legitimate exercises of a state's right to conduct its affairs with others as it pleases or undue interferences in the affairs of another state.
A third area of dispute involves the validity of consent to intervention. Many legal experts contend that intervention is legal if it is carried out pursuant to treaty rights or in response to an invitation by an incumbent government. Others dispute the legality of such interventions because treaties granting the right to intervention and requests for intervention frequently spring from duress or are initiated by unrepresentative governments eager to keep themselves in power. Whether these factors invalidate the consent expressed in the treaty or invitation is a controversial legal question. For example, when Colombia refused the request of President Theodore Roosevelt's administration to allow the United States to build a canal in Panama, then a part of Colombia, an uprising leading to Panama's independence was engineered with U.S. support. The pro-independence forces then requested U.S. aid in resisting Colombia's efforts to prevent the secession. The United States complied, ignoring Colombia's objections that the rebels lacked legitimacy and the right to request foreign aid. Once independent, Panama granted the United States the canal rights that its parent state had refused.
A related problem involves the right of collective intervention. For example, member states of the United Nations have agreed in principle to collective interventions. Is this tantamount to automatic approval of interventions by the United Nations in a member country that has violated UN rules and demands? Can a nonmember of the United Nations validly argue that collective intervention directed against it is illegal because it has not given prior consent? For example, could Iraq contend that the UN coalition cobbled together by the Bush administration in 1990–1991 amounted to illegal intervention when Iraq claimed that its incursions into neighboring Kuwait were legitimate because part of the region legally belonged to Iraq? Moreover, Iraq claimed that the government of Kuwait was ruling the country against the objections of the Kuwaiti population.
The official position of the United States on legality and illegality of interventions has generally leaned toward a fairly broad construction of the right of intervention. Presidents and secretaries of state have argued since the end of World War I that international law permits states to retain the right to determine which of their national interests may be protected through intervention and the occasions when intervention is required. Likewise, the United States contends that states retain the right to intervene individually when collective intervention machinery fails to operate efficiently. At the same time, the United States has narrowed the scope of American interests defined as vital enough to justify protection through intervention. Examples of circumstances claimed as justifying intervention include the establishment of Soviet missile sites in Cuba in 1962 and aid to the corrupt but noncommunist government of Vietnam in the 1960s when communist forces attempted to wrest power from the regime of President Ngo Dinh Diem.
The determination of what constitutes legal intervention has been further complicated by the fact that it is deemed derogatory to charge a government with the practice of intervention. For many of the world's governments and people, interventions are policies pursued by international bullies and oppressors, while nonintervention is the hallmark of virtuous nations. These evaluative connotations tempt intervening governments to avoid the label of "intervention" even when their actions are lawful. Instead, they use deceptive names, such as "interposition" or "police action." Similarly, they may misrepresent illegal interventions as legal activities by using deceptive names or spurious legal justifications. The countries that are the targets of interventions may give the false taint of illegality to them by attaching the intervention label to them. Such misuses of political terms make it difficult to ascertain prevailing views within the community of nations on the precise nature of intervention and the criteria by which one can judge whether intervention has occurred and is legal or illegal.