In contrast to strictly military forms of intervention, foreign humanitarian and relief agencies have intervened in response to civil disasters without necessarily acquiring the approval of the national government. Such intervention may be presented by the forces in place as an infringement of their national sovereignty.
Since 1970, international nongovernmental groups have intervened in countries such as Afghanistan, Ethiopia, Cambodia, El Salvador, Romania and South Africa, with or without official permission. When ejected, they in some cases returned to work clandestinely. The UN has intervened in the internal affairs of a number of countries, including Iraq, Yugoslavia and Haiti. In 1991, the UK and France (with the EEC/EU), Canada and Scandinavia were leading a campaign to radically strengthen the role played by the UN in providing humanitarian assistance. This continues to break down the taboo against UN involvement inside a country's borders. Opposition to the reforms was expressed by the Group of 77 developing countries, led by Mexico and Brazil, where it is feared that Western nations are looking for an excuse to interfere in the affairs of developing countries.
Most forms of foreign intervention with political, economic or military objectives are readily presented as being humanitarian in nature and in the best interests of vulnerable groups within the national territory.
The right to interfere means that a request from those who are suffering is sufficient to justify crossing a border without authorization from a country's leaders. The humanitarian imperative takes precedence over non-interference and sovereignty, especially where officials obstruct relief efforts or the government is overwhelmed by the dimensions of a national disaster.