Israel’s leaders must hope their army’s latest atrocity at Beit Hanoun does not trigger a knock-on, escalating regional crisis, as happened this summer when Gaza clashes laid a path to all-out war with Hizbullah in Lebanon. Rarely have situations on the ground in Palestine and across the Middle East been so tense, so interlinked, or so combustible.

Hamas hardliners are now calling on their fighters to join Islamic Jihad in stepping up attacks on Israeli targets. This raises the spectre of resumed suicide bombings. Divisions over a response to Beit Hanoun have also undercut efforts by Fatah and Hamas moderates to create a national unity government with which Israel might deal.

The Palestinian president, Mahmoud Abbas, is currently fighting a losing battle. He warned Israel after Beit Hanoun: “You are destroying all chances for peace ... You must bear all the consequences of these crimes.” He knows continuing western ostracism of Hamas, and the absence of even a pretence of a peace process, are pushing events beyond his control.

As was the case last July, Hizbullah was quick to exploit the Gaza mayhem. Its leader, Sayyed Hassan Nasrallah, mocked the impotence of Arab rulers. “Where is the scream of anger in the face of the butchers?” he asked. “The world stands silent.”

That was not exactly true. International condemnation has rained down on Israel. But Hizbullah likes to style itself a lone warrior for justice.

Rising tension suits Nasrallah’s other purposes. He is threatening to bring down the pro-western Lebanese government unless his party and its allies get a bigger share of power. And another row is developing over United Nations plans for a tribunal to try suspects in the assassination of the former Lebanese prime minister, Rafik Hariri, with leading Syrian officials likely to be fingered next month.

Notwithstanding British Prime Minister Tony Blair’s potentially conflicting attempt to engage Syria, all this prompted the US to warn last week that Hizbullah, Syria and Iran were conspiring in a coup d’etat in Lebanon. That was rejected in Damascus which, as usual, detected an American-Zionist plot.

Iran’s president, Mahmoud Ahmadinejad, meanwhile, has been encouraged by the confrontational atmosphere to propagate his weird, inflammatory views. “The Zionist regime was established in order to swallow up the entire region and to place it at the disposal of the world forces,” he told Iranian television last month.

Amid so much irrationality, hatred, instability and distrust, fears that Lebanon may catch fire again are gaining ground. An International Crisis Group report this month noted that while the United Nations’ ceasefire resolution in August “halted the fighting between Israel and Hizbullah, it did little to resolve the underlying conflict and, if poorly handled, could

help reignite it ... The temptation by either party to overreach could trigger renewed fighting.”

But as has long been the case, the United States alone has sufficient power and influence to rein in Israel, bring the Palestinians to the table, defuse the Lebanon crisis and neutralise Syria and Iran. And just as the region appears to be getting into ever bigger problems, Washington is increasingly focusing on getting out of Iraq. —The Guardian