Lieberman jumped in. He suggested that Obama doesn't have the backing to apply such pressure. "Any attempt to pressure Israel, to force Israel to the negotiating table by denying Israel support, will not pass the Congress of the United States," he said.

McCain said he agreed with Lieberman and added that he would oppose such a policy.

In a clear sign that this political attack was a farce, during the same press conference Lieberman acknowledged that the Obama administration had already disavowed the threat.

Peace for Israel is too important an issue for this kind of cheap shot.

Click here to tell your senators that they should support peace for Israel, not play petty politics.

Sadly, the loser in this type of political game is peace.

Credible diplomacy requires American and Israeli officials to sometimes disagree. Real diplomacy is not all smiles and handshakes. And without credible American diplomacy, the chance of achieving Israeli-Palestinian peace - peace that is vital for Israel's future and for American national security interests - is almost nil.

It has long been a tradition in American diplomacy that members of Congress refrain from criticizing U.S. policy on foreign soil. McCain and Lieberman do Israel no favors when they break this tradition.

McCain and Lieberman's entre into this minefield was not limited to rhetoric. Instead of engaging on a credible fact-finding mission of the settlements (the kind of trips often organized for members of Congress by Peace Now), they allowed themselves to be hosted by settler organizations while visiting some of the most hotly contested sites in East Jerusalem.

We need your help to tell Washington that it's time to stop using Israel's future as a political football. Active U.S. diplomacy is essential to the renewal of negotiations to achieve a two-state solution. Our senators should support such diplomacy.

Click here to tell your senators that they should support peace for Israel, not play petty politics.