Are Israeli settlements in the West Bank illegal? The United Nations General Assembly, the UN Security Council and the International Court of Justice have all said that Israeli settlements on the West Bank violate the Fourth Geneva Convention. Israel captured the West Bank from Jordan in the 1967 war and has occupied the territory since. The Fourth Geneva Convention, ratified by 192 nations in the aftermath of World War II, says that an occupying power "shall not deport or transfer parts of its own civilian population into the territory it occupies". The statute that established the International Criminal Court in 1998 classifies such transfers as war crimes, as well as any destruction or appropriation of property not justified by military necessity. Israel argues that a Jewish presence has existed on the West Bank for thousands of years and was recognised by the League of Nations in 1922. Jordan's rule over the territory, from 1948 to 1967, was never recognised by most of the world, so Israel also argues there was no legal sovereign power in the area and therefore the prohibition on transferring people from one state to the occupied territory of another does not apply. The International Court of Justice rejected that argument in an advisory opinion in 2004, ruling that the settlements violated international law.

The Israeli Supreme Court and the government do consider settlement construction on privately owned Palestinian land to be illegal. The announcement is a boost for Benjamin Netanyahu, who is in danger of losing power after the recent election. Credit:Reuters Under the Oslo Accords, signed by Israel and the Palestinians in the 1990s, both sides agreed that the status of Israeli settlements would be resolved by negotiation. However, negotiations have stalled and there have been no active peace talks since 2014. What are the settlements? Israel has built about 130 formal settlements in the West Bank since 1967. A similar number of smaller, informal settlement outposts have gone up since the 1990s, without government authorisation but usually with some government support.

More than 400,000 Israeli settlers now live in the West Bank alongside more than 2.6 million Palestinians. Some of the settlements are home to religious Zionists who believe that the West Bank, which Israel refers to by its biblical names of Judea and Samaria, is their biblical birthright. Many secular and ultra-Orthodox Jews also moved there largely for cheaper housing. Palestinians and Israeli activists run away from tear gas fired by Israeli soldiers during a 2016 demonstration against the construction of Jewish settlements in the Jordan Valley. Credit:AP Some settlements were strategically located in line with Israel's security interests. Other, more isolated communities were established for ideological reasons, including an effort to prevent a contiguous Palestinian state. Israel also captured East Jerusalem in 1967, and annexed it. The Palestinians demand East Jerusalem as the capital of a future state, and much of the world still considers it occupied territory.

Most of the world views the expansion of Israeli settlements as an impediment to a peace agreement. While most blueprints for a peace agreement envisage a land swap - Israel retains the main settlement blocs, where a majority of the settlers live, and hands over other territory to the Palestinians - the more remote and populated the settlements, the harder that becomes. What difference will the US policy make? Netanyahu, who is fighting to remain prime minister after two inconclusive elections, has promised to annex the settlements and the strategic Jordan Valley, constituting up to a third of the West Bank. In June the US ambassador to Israel, David Friedman, said Israel had a right to retain at least some of the West Bank. The Trump administration's declaration may be seen by supporters of the settlement enterprise as giving a green light to Israeli annexation plans. But Israeli experts cautioned that might not be the case.

"It's one thing saying the settlements are not in violation of international law and another to say whether they are good for peace or not," said Michael Herzog, an Israel-based fellow with the Washington Institute for Near East Policy. The Trump administration neither rejected nor endorsed Netanyahu's annexation proposal, he said, and it remains "an open question" how it would react if Israel unilaterally annexed West Bank territory. A helicopter takes off carrying Prime Minister Benjamin Netanyahu after a cabinet meeting in the West Bank. Credit:Reuters He and others said that while the policy change could affect the public perception of the settlements, the legal question would have little bearing on a comprehensive peace deal, which is ultimately a political act. "The settlements are an agreed upon issue for negotiation between Israel and the Palestinians," said Alan Baker, a former legal adviser to the Israeli Foreign Ministry. "It's an issue that has yet to be negotiated." But in the absence of negotiations, the US policy could be used to justify even more settlement construction.