The most important battle in the Middle East is the one taking place between President Obama and the Congress. It centers on the maneuvering by the President and Secretary of State Kerry to reward the Iranians far more than the administration disclosed to Congress at the time it presented the articles of appeasement to the House and Senate in the first place. It’s too soon to gauge which side will win this fight, but it’s not too soon to say that it could be historic.

There are going to be those who say that the question of which branch has primacy in foreign affairs was settled in Zivotofsky. That was the Supreme Court case in which the Nine concluded that the president had the sole authority to decide whether an American born in Jerusalem should be given papers saying he was born in Israel. But that was a narrow question, centered on what is called the “reception” power — the power to receive ambassadors.

What is building now is a struggle over who has the power to regulate commerce with foreign nations. This is because what Secretary Kerry is plotting is a scheme to restore to the Ayatollah Khamenei and his camarilla access to the American banking system. It is covered in the third great grant to Congress, the power to “regulate regulate commerce with foreign nations, and among the several states, and with the Indian tribes.” It’s going to be hard to deny Congress a say in this one.

Clearly it’s going to want to be heard. One of Ways and Means subcommittee chairman, Peter Roskam, is out this week with a piece on the Wall Street Journal editorial page warning American — and, one can add, foreign — businesses against the temptation to engage in commerce with the Iranian regime. The ayatollahs may be welcoming foreign investment with “open arms,” he writes, but “if you wouldn’t do business with Islamic State, you shouldn’t do business with the Islamic Republic.”

That Congress is spreading this alarm clearly has the administration in a swivet. It was bad enough that it decided to proceed with an agreement that was opposed by majorities in both houses. But what the administration is trying to do is slip Iran relief even from the non-nuclear sanctions. Or, as Omri Ceren of the Israel Project puts, the administration is saying two things — that American should push back against Iran’s provocations and that “the nuclear deal may require the U.S. to avoid pushing back against these activities.”

From the outset of this whole sorry affair, the Sun has opposed treatment with the Iranian regime. Our view has been that the appeasement is in the talking. The latest apologetics by the State Department are about exactly what we were worried. It is a tragedy for President Obama and Secretary Kerry (they will be remembered like Chamberlain and Halifax). But Congress clearly has the constitutional grant of power to regulate commerce with Iran in as tough a way as it possibly can.