Is the Wall legal?

The Wall in the West Bank is a combination of an eight meter high concrete wall and/or ditches, trenches, fences, razor wire, electronic fences and military roads. Israel  began its construction for security reasons in 2002, after a wave of suicide attacks,  and is still continuing the construction today .

The Advisory Opinion of the International Court of Justice

The Advisory Opinion of the International Court of Justice (ICJ) from 9 July 2004 on the legal consequences of the construction of a wall inside the occupied Palestinian territory (oPt) stated that the Wall built on West Bank land including East Jerusalem, is illegal. The ICJ was requested by the UN General Assembly to issue an advisory opinion and decided by 14 votes to 1 to comply with that request.
Read more about the ICJ Advisory Opinion

Israeli High Court of Justice Rulings

The Israeli High Court of Justice (HCJ) has given several principal rulings on the legality of the Wall. The first case was the Beit Surik ruling. The petition was filed by the local council of Beit Surik village against the government of Israel and the Israel Defence Forces (IDF) military commander in the West Bank. On 30 June 2004, nine judges decided that the construction of a Wall on the West Bank land was not illegal per se. They claimed that the Wall, as a security measure, is legal even if built inside the West Bank since it is temporary in nature and since it was built for security reasons, and follows the requirement of military necessity according to IHL.
Read more about military necessity
To the full version of the Beit Surik Ruling
Read more about rulings from the Israeli High Court