But there's a huge difference between that and engaging terrorists in the public square, which gives them respectability, legitimises their "grievances" and validates their strategy of using violence to achieve political ends.

Such appeasement lies at the very heart of the eight-decade Arab-Israel conflict. When the Arabs used violence to thwart the 1920 League of Nations decision to re-establish a Jewish national home in Palestine, Britain responded not by enforcing its mandate to set up the home but by giving half of it to the Arabs.

The terrible lesson that violence pays has been repeated over and again in the Middle East. After the very first plane hijackings in the 1960s, the West responded by giving Palestinian terrorists a respectful hearing on the (spurious) grounds that their cause, if not their tactics, was legitimate. It treats Mahmoud Abbas's Fatah as a legitimate negotiating partner, despite its continuing involvement in terrorism, incitement to hatred of Israel and its declaration that it will never accept Israel as a Jewish state. Now people want to exacerbate that appeasement by talking to Hamas and Hizbollah. Obama has actually suggested that they have "legitimate claims". But what are they?

Their agenda - the destruction of Israel, the killing of every Jew - is both unconscionable and non-negotiable. "We are not fighting so that you will offer us something," said Hussein Mussawi, a former leader of Hizbollah. "We are fighting you to eliminate you." Talking to terror régimes empowers mass murderers and undermines moderates. So why is this disastrous proposal now running so strongly? One key factor is Northern Ireland, where the British establishment has convinced itself that it brought about peace by talking to the IRA. The IRA itself renounced violence because it had been beaten into a stalemate by the Army.