Yesterday marked President Barack Obama’s first 100 days in office. An entirely arbitrary construct to evaluate a leader’s performance, it is nevertheless irresistible when it comes to Obama, of whom expectations are so high.

His first priority was always going to be the global financial crisis. The massive stimulus package has yet to work its way down and out and it is impossible to say anything other than that Obama has tackled the crisis immediately and with enthusiasm.

Of more concern here is the US foreign policy. Obama proved true to his word that he would change the tone of America’s relations with the rest of the world.

Relations with Russia have thawed; relations with Europe have become positively giddy. He has lifted travel restrictions on families in America wishing to visit Cuba and begun to heal relations with Venezuela.

Towards the Muslim world, he has made a number of significant moves. He toned down the rhetoric on Iran at a crucial time, and set a deadline for withdrawal from Iraq. He chose Turkey, a democratic Muslim country, as the venue to deliver a speech of conciliation with the Muslim world.

His Majesty King Abdullah was the first regional leader to visit Washington, even before the Israeli prime minister.

Obama’s handling of the Palestinian-Israeli conflict is vital. No American president will fully gain the trust of the Arab world or, indeed, the Muslim world, until he demonstrates that he is an unbiased and serious mediator between Palestinians and Israelis.

In this context, the appointment of George Mitchell as Middle East peace envoy was a significant positive step. So was the US insistence that a two-state solution is not only America’s preferred end to a peace process, it is an American national interest. The stage seems set for a US-Israel showdown.

Now comes the crucial time. Setting mood lighting is all well and good, but the food has to be properly prepared, the music well chosen and the conversation just so. It is time to deliver.

Obama needs to spell out what he means by a two-state solution. This has to be a vision that is in line with international law, no ifs and buts. Should the US do so, it will receive the support of the entire Arab world.

Then the US administration needs to take on the pro-Israel lobby and the US Congress. Only then will we know how serious and dedicated Obama is to peace in this region.

It’s a long battle, but one that he will not have to fight alone if he sets out his stall well.