On Tuesday, five intense days of showdown between President Obama and visiting Israeli Prime Minister Benjamin Netanyahu ended with the prime minister delivering a bombastic address to a joint session of Congress. The standoff began the week before, when Netanyahu objected furiously and publicly to a speech where Obama suggested that the starting point for negotiations over a Palestinian state should begin with the legal borders of Israel before the Six-Day War in 1967, when Israel seized the West Bank and other Palestinian territories. Obama responded with a careful speech before AIPAC, the country's most powerful pro-Israel lobby, and Netanyahu finished with his rare address before the American legislature.

Netanyahu's reaction, as well as that of many American politicians from both parties, illustrated how politically perilous it is for a president to cross Israel. Obama's proposed peace plan isn't holy scripture, but neither is it bold or unprecedented. Negotiating a Palestinian state from the pre-1967 borders has been the assumed (though not explicitly stated) core of America's Israel policy for decades. It has been embraced by two previous Israeli leaders, and has the support of most of the international community. But by saying it aloud, Obama is "throwing Israel under the bus," according to Mitt Romney, and "disrespecting an ally," according to Sarah Palin. Coloring his rebuke of Obama just a shade lighter, Senate majority leader Harry Reid said, "No one should set premature parameters about borders."

I suspect most Americans look on the Israel-Palestine controversy, quite rightly, as distant, complex, and perplexing, if not utterly impossible to form a sound opinion about. Most people would probably read my previous two paragraphs and not quite get what all the fuss is about. I don't quite get it, either. But what I saw from Washington's power brokers over the past week—vicious attempts to enforce orthodoxy, hysterical determination to shut down debate, and theatrical sycophancy toward a foreign leader—are so alarming that they must be addressed. If we are ever to arrive at a sensible Mideast policy, this kind of irrationality clearly will not do.

There is nothing wrong, of course, with American politicians strongly supporting Israel, and favoring policies that enhance its security. But close alliances naturally come with expectations; America's allies have arguably even more responsibility than others for behaving as morally and legally as we expect our own government to behave. Although its enemies are deadly and unrelenting, Israel has, in its short history, regularly pushed the boundaries of legality and humanity, from its persistence in violating international border agreements to its unrepentant displays of gratuitous violence. Settlement-building excepted, American administrations under both parties have rarely dared to condemn the excesses.