Barack Obama and his team have taken a much tougher line towards Israel this week than any other US president for almost two decades. That is part of his plan for redrawing America’s relations with the region and the Muslim world, a vision he plans to set out in a landmark speech in Cairo on Thursday. It is just words, so far, but he has made it clear that he wants a real drive for an Israeli-Palestinian deal to lie at the heart of it. The new Israeli Government, given a very clear warning this week by the Obama team, must decide whether to call Mr Obama’s bluff, or accept his demand for a freeze on West Bank settlements.

Yesterday’s meeting between Mr Obama and the Palestinian leader Mahmoud Abbas was never going to be decisive. How could it be, when the split in the Palestinians between Abbas’s Fatah and the Islamists of Hamas remains one of the big obstacles to talks? But it was a necessary step in the careful path Mr Obama is laying out. So, too, was his recent meeting with Binyamin Netanyahu, Israel’s Prime Minister, and the meetings he will have in Saudi Arabia on Wednesday, as well as in Cairo the day after.

The shock to the Israeli team this week will have come from Hillary Clinton, the US Secretary of State. She said that in his meeting with Mr Netanyahu, Mr Obama was absolutely clear: the US wanted an immediate freeze on all building or expansion of Israeli settlements in the West Bank. By that he meant a freeze on new outposts — and an end to expansion of existing ones.

Israel has used “natural expansion” as a loophole through which to pursue the growth of settlements on land captured in the 1967 war. The spread of the buildings, which are considered illegal under international law, has accelerated in recent years, despite Israel’s past promises to stop. Some settlements are just clusters of dwellings. Others are large towns, with roads, schools and highways connecting them to Israel, which Palestinians are forbidden to use. The World Bank has said that the overwhelming majority of the intrusions into Palestinians’ land are to support the settlements, not Israel’s security needs to protect itself against terrorism. Palestinians fear that if they ever win a state of their own, there would be only a “Swiss cheese” remnant of the West Bank left for them, together with the Gaza Strip.

On Sunday Mr Netanyahu told his Cabinet, according to aides, that he did not intend to build new settlements “but it makes no sense to ask us not to answer to the needs of natural growth and to stop all construction”. Mrs Clinton told him he was wrong to think that Mr Obama would support any exceptions at all. Will Mr Obama go as far as George Bush Sr - who had threatened to cut off financial support if Israel refused to comply? We don’t know, although such direct confrontation is not Mr Obama’s style. But coming before his arrival in Arab countries, he has given a strong message that he intends to put overt pressure on Israel to play its part in restarting talks.

Not all his points are harsh towards Israel. A week from today he is expected to visit Buchenwald Nazi concentration camp, where his great-uncle took part in the liberation. That is an important gesture. But that does not change the decision that now confronts Israel’s Prime Minister, of how to respond to a US President who has demanded, unambiguously, a real change.

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