By Nick Miles
BBC News, Washington
Since the start of the current violence in Lebanon, the United States' position has remained consistent: it is only sensible to have an Israeli ceasefire when it can be a sustainable one.
US demonstrators have been out in the streets backing Israel
In other words, when Hezbollah has been sufficiently weakened to no longer pose a threat.
That is a view that has been at odds with many European nations, who have argued for an immediate Israeli ceasefire.
The reasons for that difference in emphasis are complex but many people point to the power of the Israel lobby in the United States as a key factor.
The leading organisation trying to secure US support for Israel is Aipac, the American Israel Public Affairs Committee.
Aipac is a special interest group established more than 50 years ago.
Today it has more than 100,000 members across 50 states.
It regularly holds meetings with members of Congress and provides analysis of the voting records of US lawmakers.
'No dark caves'
Whilst Aipac is the largest pro-Israel group in America, there are many other organisations representing Jewish interests in the US - interests that often coincide with those of Israel.
"There's not a great conspiracy where at seven o'clock in the morning we meet in a cave and discuss strategy together," says William Daroff from the United Jewish Communities, an umbrella organisation for American Jewish groups.
"Of course we speak with other Jewish groups about Israel, but there's no co-ordinated programme."
United Jewish Communities is just one of a number of organisations promoting Israel's interests in Washington.
Stephen Walt of Harvard University's Kennedy School of Government co-wrote a recent paper outlining what he regards as the power of the Israel lobby on US policy.
"They can help you or hurt you, depending on whether or not they like what you stand for," he told the BBC in a recent interview.
Part of the power wielded by the lobby is electoral.
Jewish voters make up less than 3% of the US electorate but they are an important voting block.
Historically the majority of them have voted for the Democratic Party.
There is some evidence that is changing.
Over the last 20 years a new generation of young Jewish voters seems to be more evenly split in its loyalty to the two main parties.
Back in 2000, the Jewish vote in Florida was a key factor in the Republican victory there, and by extension nationwide.
But Israel also gets support from another, far larger voting block - evangelical Christians.
More than one in three Americans describe themselves as "born-again" or "evangelical" Christians, according to the Pew Forum on Religion & Public Life.
Last month Pastor John Hagee led a 3,400-strong delegation to Congress in support of Israel.
He leads a group called Christians United For Israel, which regards support for Israel as a religious imperative.
"Israel is the only nation Christians are told to pray for in the Bible," he said in a recent interview.
"Because the Bible is the compass of our faith, we do what it says. Every anti-Semite is going to spend eternity in hell without God."
Clearly the pro-Israel lobby in the United States is significantly stronger than in European nations, for example.
So it is not surprising that Israel receives significantly more financial assistance from the United States than from any other country.
Every year, $3bn flow from the US to Israel in economic and military aid.
Israel has been Washington's largest recipient of aid for 30 years.
The prevailing political culture in the United States may appear to favour Israel.
But that mood is not necessarily shared by all Americans.
A recent poll in the New York Times suggested that a slight majority of Americans feel their government should not be unquestioning in its support for Israel's war against Hezbollah.
If that begins to influence congressmen against supporting Israel, the power of the Israel lobby will be put to the test.