A state cannot appropriate the territory of another state: it is a concept that should be obvious. The UN Statute, moreover, prohibits use strength To resolve international conflicts and, consequently, he does not admit neither military occupations nor annexes. In fact, however, the UN hardly manages to impose respect for the rules, because it clashes with two difficulties: rarely the member countries find an agreement to take a decision; Even when they succeed, the UN does not have the tools to enforce the rules. Consequently, in international relations the force is used frequently And in some cases states occupy or even annex territories of other countries. And this is precisely the case of what is happening between Israel and Palestine.
What are the annexes of territories and military occupations
Annexing a territory means appropriate and declare one’s sovereigntymaking it part of a state. An example is Jerusalem Estoccupied by Israel in 1967, when it belonged to Jordan, and officially annexed in 1980 (the status of Gaza and the West Bank is different, so far not formally annexed).
Military occupation is instead thetemporary intake of the control of a territory: a state occupies the territory of another country with its armed forces, in whole or in part, and the government with its authority. An example is theAllied Military Government (Allied military government), which administered some sectors of Europe during the Second World War, before the control was “returned” to the national authorities. In some cases, military occupation is the premise for annexation.

International law, UN and the use of force
International law, logically, does not recognize unilateral annexes (that is, with the use of force and without agreement between the parties): they are equivalent to taking something that is not exactly. However, sometimes contrasts arise between states and annexations are declared because Some territories are claimed by more than a political authority. Think, for example, of Crimea and Donbass, claimed by Russia and Ukraine.
Who should prevent annexes is the UN, the international body of which all the states of the planet are part. The UN Statute prohibits the use of force to resolve international contrasts. It reads in article 2:
Members must resolve their international disputes with peaceful means, so that international peace and security, and justice, are not endangered.
Members must refrain in their international relations from the threat or use of force, both against the territorial integrity or political independence of any state, and in any other way incompatible with the purposes of the United Nations.
The only admitted exceptions are the right to defense (article 51), the Actions against ex enemies during the Second World War (article 107, now obsolete) and the Interventions authorized by the Security Council Against countries that threaten or violate peace (articles 39-50). Occupations and annexes would therefore be prohibited.

Sanction those who violate international law: the limits of the UN
Although in prohibited theory, many states use military force to assert their reasons and sometimes even unilateral annexes of territories take place. In fact, in demanding respect for the statute, the UN clashes with two difficulties.
Difficulty of finding an agreement between the States
Rarely the UN manages to express a univocal location On a question, because the states that make it up have divergent interests. More specifically, the most binding resolutions issued by the UN are those of Security Councilcomposed of representatives of 15 countries: five permanent and ten in rotation. The five permanent members (USA, Russia, China, France, the United Kingdom) have right of veto And, therefore, it is enough that one is against to block the resolutions.

For this reason, the UN did not condemn, for example, The Russian invasion of Ukraine: the penalties have been imposed by individual countries (such as the United States) and by other international bodies (the European Union), but not by the United Nations. The United States, in turn, have used the power of veto many times, in most cases to block Resolutions that condemn the state of Israel for his violations of legality.
Instead, no state has the right to veto on the resolutions of the General Assembly, made up of representatives of all countries, but the resolutions are not binding.
Lack of coercive means to enforce decisions
Even when the UN manages to find an agreement, it does not have tools to make it respect. An example is the Resolution 242 of 1967with which the Security Council imposed on Israel to return the territories busy during the Six days warincluding Gaza and the West Bank. Since then, Israel has only returned Sinai to Egypt.
The resolutions of the General Assembly are in turn often ignored. For example, the assembly has repeatedly asked for the end of theembargo imposed by the United States against Cuba Since 1962 (the last time, in a large majority, in 2024), but the embargo is still in force.

The UN manages to assert its reasons only when the relationships of strength allow it And the resolutions “cover” decisions that, in reality, have been taken from the main powers. An example is the First Gulf War. In 1990 Iraq declared the annexation of Kuwait and the UN authorized the use of force to free the territory; In 1991 an international coalition attacked Iraqi troops and forced them to retire. The intervention, in reality, was wanted by some countries, including the United States, which at that moment exercised an almost absolute hegemony, having now defeated the Soviet Union in the Cold War: if the United States had been against, the UN could not have imposed respect for legality at Iraq.
Peacekeeping missions and blue helmets
The UN can organize Peacekeeping missionsthat is, send soldiers and civil staff for the maintenance of peace in areas affected by conflicts. The missions are authorized by the Security Council, generally with the agreement of the parties involved. Since the 1960s, they have been organized Dozens of missions around the world And some are currently underway.

During the missions, the UN can deploy an interposition force, the so -called blue helmetsprovided by the Member States, who have different assignments and armaments depending on the mission. In some cases, Peacekeeping missions have prevented the resumption of conflicts and protected human rights. However, they have not always managed to pursue the purposes for which they are organized. The example in which their impotence was more evident is the 1995 Srebrenica massacre: 600 blue helmets were lined up in the area, which however did not intervene and let the Serb-Bosnian militias assassinate thousands of people.
Sources
Peter Stirk, The Politics of Military Occupation, Edinburgh University Press, 2009
Heather Docalavich, The History, Structure, and Reach of the Un, Mason Crest, 2015
History of the United Nations
