The notion that “politics stops at the water’s edge” hasn’t prevailed for much of U.S. history, but the current level of foreign-policy partisanship is dangerous to national security.

Instead of uniting in the face of mortal danger – the threat of Islamic radicals intent on acquiring nuclear weapons – Republicans, Democrats and their rhetorical allies are busy savaging each other.

When the United Kingdom broke up the plot to blow up U.S.-bound airliners over the Atlantic Ocean, it should have been a reminder of a common threat we all face.

Instead, Democrats took the opportunity to blast the Bush administration for wasting resources on Iraq while Republicans sought to prove once again that Democrats are weak on terrorism.

In the meantime, the Islamic radical group Hezbollah has won a public relations victory against Israel and a strategic victory over the government of Lebanon – and America’s enemies, Iran and Syria, are cheering.

The fighting in Lebanon diverted world attention from Iran’s nuclear program, which proceeds apace, and served to divide a coalition of Arabs, Europeans and Americans determined to resist the spread of Iranian influence.

It’s probably impossible, on the merits and in an election year, to achieve unity on all the policies necessary to cope with the multi-phased threat facing the West. But it’s a time for sober, serious debate – not name-calling and point-scoring.