If we needed further proof of the Republican disrespect shown to President Obama, the nation witnessed the latest insult Tuesday with the visit of Israel’s Prime Minister Benjamin Netanyahu to Washington, where he addressed a joint session of Congress.

His appearance was at the invitation of House Speaker John Boehner, a Republican who flouted protocol and decency by neither consulting nor informing the White House first.

We had hoped that Mr. Boehner or Mr. Netanyahu would have come to their senses and either canceled or postponed the event. But the fact that they went ahead with the address shows the disdain they both have for President Obama and his authority.

Politicians both in the United States and Israel thought the invitation and the speech both inappropriate and ill-advised, in part, because of its timing. Mr. Netanyahu is up for re-election in two weeks and could use the platform to increase his chance of winning, while the United States — through Secretary of State John Kerry — currently is in delicate negotiations with Iran over its possession of nuclear technology. By having the hawkish prime minister to speak, Mr. Boehner would only undermine President Obama and his administration’s efforts to negotiate a deal with Iran.

In a nearly hourlong address to a chamber filled with applauding Republicans, Mr. Netanyahu slammed President Obama’s diplomatic initiative for peace. Playing up the fear factor, the prime minister charged that instead of stopping Iran from obtaining nuclear weapons, President Obama’s multilateral proposed nuclear deal would “pave Iran’s path to the bomb.” He said the U.S. should demand that Iran stop its aggression against neighbors and its threats to annihilate Israel.

While most foreign dignitaries who address Congress bring messages of harmony and accord, Mr. Netanyahu’s rhetoric served only to fuel Republican efforts to turn the question of negotiations with Iran into a divisive political issue, along with a senseless script about who loves Israel best — the Democrats or the Republicans.

After Mr. Netanyahu’s speech, Senate Majority Leader Mitch McConnell, a Republican, moved to push to the floor next week legislation that would require President Obama to submit to Congress for a vote any deal the United States signs with Iran to curb its nuclear program. Proposed legislation also would restrict President Obama’s authority to waive any of the current economic sanctions against Iran, allowing Congress 60 days to review any such plan.

The danger is not in negotiating with Iran. The danger is in listening to Mr. Netanyahu, whose plan to protect Israel includes drawing the United States and a host of other nations into military action against Iran.

His brand of politics is whipping up further division in a Congress already paralyzed by partisan extremism. And his fear mongering and warmongering may drive Iran from the discussions now taking place in Geneva, Switzerland.

As one veteran said, “I don’t appreciate Republicans placing our security in the hands of a foreign leader just because they hate our president.”

The GOP’s animosity for President Obama is pushing us toward more war and a path of regret. If the debacle of Mr. Netanyahu’s visit teaches us anything, it should be the importance of working across the political aisle — and the globe — for peace.