WASHINGTON (AFP) - Washington's unconditional and unflinching support for Israel during its 34-day bombing of Lebanon last year dealt a key blow to US influence in the Middle East, already eroded by the Iraq war.

"I do not think the US credibility in the Arab street had held much weight before the (Lebanon) war anyway. So the damage had already been done," said Middle East expert Hesham Sallam from the United States Institute for Peace.

"But what the war did was reinforce a growing perception in the region that the US will stand by Israel no matter what."

Israel retaliated after Hezbollah guerrillas infiltrated across the border with Lebanon, attacking two army vehicles on July 12, 2006. Eight Israeli soldiers were killed by the Shiite militants in separate attacks and two more were captured.

As the casualties mounted on both sides, France and Arab allies of the United States pleaded for a ceasefire.

But for weeks Washington turned a deaf ear to international pleas to exert its influence on Israel and bring about an end to hostilities.

By the end of the war 1,200 Lebanese and 162 Israelis had been killed. Thousands had fled Lebanon in a mass exodus, and Hezbollah strongholds in the south and Beirut lay in ruins.

When US Secretary of State Condoleezza Rice finally flew to the region at the end of July 2006 she was loudly condemned for describing the devastation as the "birth pangs of a new Middle East."

Many Arabs took her remarks as an insult and further proof of the US administration's general contempt for the Arab world.

But Rice has defended her comments, saying recently at a Paris news conference that the Lebanese "gained a great deal" from the war which ravaged parts of their country.

Since the conflict the Lebanese army has been deployed in southern Lebanon, once a militant stronghold, and for the first time in decades it has also taken on groups of extremists holed up in Palestinian refuge camps, she says.

Rice has also seen the war as a turning point in Middle East politics, allowing moderate Arab states to align themselves with the US against the hardline regimes in Tehran and Damascus which support Hezbollah and Hamas militants in the Palestinian territories.

It is true that Egypt, Jordan and Saudi Arabia all condemned the initial Hezbollah attack which unleashed Israel's military wrath.

But their condemnations went against the tide of opinion in their countries, and as the conflict progressed they were forced to make more measured public statements, Sallam said.

After Israel's deadly bombing of a UN peacekeepers' post in southern Lebanon in late July, Rice was forced to cancel a second planned trip to Beirut as US ally Prime Minister Fuad Siniora made it clear she was not welcome.

For Zbigniew Brzezinski, a former national security adviser to ex-president Jimmy Carter, the influence of the United States in the Middle East has waned since the 2003 invasion of Iraq.

"We are the only superpower. But our leadership is being tested in the Middle East, and some of the things that we have done in the Middle East are contributing to a potential explosion region-wide," he said.

"And if that explosion gets out of hand, we may end up being bogged down for many years to come in a conflict that will be profoundly damaging to our capacity to exercise our power."

But Rice fiercely rejects accusations that US interference is destabilising the fragile region.

"What stability? The stability in which Saddam Hussein put 300,000 people in mass graves? That was stability? The stability in which Syrian forces were embedded in Lebanon? That was stability?" she asked in Paris.

"The stability that produced Al-Qaeda to, on one September day, cause 3,000 American deaths?"