Javier Pérez de Cuéllar in the context of Prime minister of Peru

The Brundtland Commission, formally the World Commission on Environment and Development, was a sub-organization of the United Nations (UN) that aimed to unite countries in pursuit of sustainable development. It was founded in 1983 when Javier Pérez de Cuéllar, the Secretary-General of the United Nations, appointed Gro Harlem Brundtland, former Prime Minister of Norway, as chairperson of the commission. Brundtland was chosen due to her strong background in the sciences and public health.

The Brundtland Commission officially dissolved in 1987 after releasing Our Common Future, also known as the Brundtland Report. The document popularized the term "sustainable development" and won the Grawemeyer Award in 1991. In 1988, the Center for Our Common Future replaced the commission.

United Nations Security Council resolution 658, adopted unanimously on 27 June 1990, after recalling Resolution 621 (1988) and noting a report by the Secretary-General on the situation in Western Sahara, the Council approved the Secretary-General's recommendations regarding a settlement of the issue.

Though not established until Resolution 690 (1991), the agreement arising from Resolution 658 concerned a plan whereby the United Nations would supervise a ceasefire between Morocco and the Polisario Front and conduct a referendum in which the people of Western Sahara would decide between self-determination or integration with Morocco that later became known as the United Nations Mission for the Referendum in Western Sahara. Secretary-General Javier Pérez de Cuéllar described the plan as "large and complicated". This was proposed after the 1988 Settlement Plan agreement between Morocco and the Polisario Front.

United Nations Security Council resolution 598 S/RES/0598 (1987), (UNSC resolution 598) adopted unanimously on 20 July 1987, after recalling Resolution 582 and 588, called for an immediate ceasefire between Iran and Iraq and the repatriation of prisoners of war, and for both sides to withdraw to the international border. The resolution requested Secretary-General Javier Pérez de Cuéllar to dispatch a team of observers to monitor the ceasefire while a permanent settlement was reached to end the conflict.

Iraq quickly accepted the resolution, but Iran refused to accept its terms until nearly a year after its adoption. Famously, Ayatollah Ruhollah Khomeini felt that accepting the resolution was "more deadly than drinking from a poisoned chalice". The resolution finally became effective on 8 August 1988, ending all combat operations between the two countries and the Iran–Iraq War.