House Speaker John Boehner has invited Israeli Prime Minister Benjamin Netanyahu to speak to a joint session of Congress in February, on the topic of Iran. On the surface, this might seem innocent enough. Israel is a close American ally. Surely he should be welcome in Congress, particularly to discuss an issue that concerns his country.

On the surface, Netanyahu's speech will be about opposing Obama's nuclear talks with Iran and supporting Republican-led sanctions meant to blow up those talks.

But there's more than meets the eye here. Netanyahu is playing a game with US domestic politics to try to undermine and pressure Obama — and thus steer US foreign policy. Boehner wants to help him out. By reaching out to Netanyahu directly and setting up a visit without the knowledge of the White House, he is undermining not just Obama's policies but his very leadership of US foreign policy. The fact that Netanyahu is once again meddling in American politics, and that a US political party is siding with a foreign country over their own president, is extremely unusual, and a major break with the way that foreign relations usually work.

Netanyahu is trying to actively undermine Obama and unseat the Democrats

Throughout Obama's tenure, he has clashed with Netanyahu. That is no secret, and it's nothing new for American and Israeli leaders to disagree, sometimes very publicly. But Netanyahu, beginning in May 2011, adopted a new strategy to try to deal with this: using domestic American politics as a way to try to push around Obama.

During a trip that month to Washington, Netanyahu publicly lectured Obama at a press conference and then gave a speech to Congress slamming the president. That speech, also hosted by Republicans, received many standing ovations for Netanyahu's finger-wagging criticism of Obama.

At first it appeared that Netanyahu was merely trying to steer Obama's foreign policy in a direction that he, Netanyahu, preferred. Obama wanted Netanyahu to freeze Israeli settlement growth in the West Bank, for example; Obama has also sought, in his second term, to reach a nuclear deal with Iran that Netanyahu earnestly believes is a bad idea.

Netanyahu's first responsibility is to Israel's national interests, not to Obama, so it makes sense that he would push for policies that he thinks are good for Israel.

But in 2011 Netanyahu started going a step further, and appeared to be working to actively remove Obama from power. During the 2012 election cycle, Netanyahu and his government were increasingly critical of Obama and supportive of Republicans, including presidential candidate Mitt Romney, for whom he at times appeared to be actively campaigning. Netanyahu's criticisms of Obama were so pointed that some of Obama's opponents cut a campaign ad out of them. It became a joke within Israel that Netanyahu saw himself not as the leader of a sovereign country, but as the Republican senator from Israel.

But trying to unseat a foreign leader is not a joke, especially when that foreign leader is funding your military and guaranteeing your nation's security.

Netanyahu's government ramped down this strategy after Obama won; he even gave Obama the world's most awkward congratulations speech. But throughout Obama's second term he has once again gradually escalated from trying to influence Obama to actively undermining both the president and his party. The new Israeli ambassador to the US for months would not even bother to meet with National Security Advisor Susan Rice, yet held many meetings with Republican fundraiser Sheldon Adelson. Israel's foreign policy, in other words, was more focused on undermining the American leadership than working with it.

Republicans are siding with a foreign country over their own president

Republicans, aware that Americans are supportive of Israel, have urged on Netanyahu's anti-Obama campaign since it began in 2011. Inviting him to speak to Congress that year was shrewd domestic politics, and it will be shrewd legislative politics next month when Netanyahu publicly supports the GOP's sanctions efforts.

This makes sense within the narrow scope of domestic politics — if you can use something to convince voters your party and its policies are a better choice than your opponents, you use it, even if that something is a foreign head of state. But members of Congress are purportedly supposed to put their country before their party, and siding with a foreign leader over your own president doesn't seem to do that. Neither does cheering a foreign leader when he lambasts the president of the United States.

More to the point, it was a really significant breach when some conservatives supported Netanyahu's implicit lobbying on behalf of the Romney campaign. If a foreign country wants to unseat your president, that is generally considered an outrageous breach. But Netanyahu has been invited in, and with the 2016 presidential elections ramping up it appears likely he will be invited in once more to implicitly run against the Democrats.

This speaks, in a very real sense, to just how extreme political polarization has become in Washington.

This sort of practice is bad for America's ability to conduct foreign policy

To be very clear, this is not just a breach of protocol: it's a very real problem for American foreign policy. The Supreme Court has codified into law the idea that only the president is allowed to make foreign policy, and not Congress, because if there are two branches of government setting foreign policy then America effectively has two foreign policies.

The idea is that the US government needs to be a single unified entity on the world stage in order to conduct effective foreign policy. Letting the president and Congress independently set their own foreign policies would lead to chaos. It would be extremely confusing for foreign leaders, and foreign publics, who don't always understand how domestic American politics work, and could very easily misread which of the two branches is actually setting the agenda. (This confusion, by the way, is exactly what some Republicans are hoping to create in Iran with new sanctions.)

This could also allow a foreign country to play those two branches off of each other. That's in part what Netanyahu is attempting to do here, and it's working. The Obama administration did not even find out about Netanyahu's planned visit to Washington until Boehner announced it. The Republicans are attempting to run a foreign policy that's separate from the actual, official US foreign policy.

One more anti-Obama speech from Netanyahu on the floor of Congress is not going to break US foreign policy, of course. But it's troubling that Republicans are willing to breach such an important principle for some pretty modest short-term gains.