The Iranian retaliation for the Soleimani assassination that we feared would happen has started:

Iranian forces have launched more than a dozen ballistic missiles against two military bases in Iraq, the Pentagon said Tuesday evening, marking the most significant Iranian attack in the growing conflict with the United States.

The al-Asad air base in western Iraq, which houses some American troops, was hit by at least six rockets about midnight Wednesday, according to a U.S. defense official familiar with the situation.

There was always going to be an Iranian military response to last week’s attack, but it is significant that the IRGC launched these attacks directly and did so from Iranian territory. If they had wanted, they could have responded by employing the militias that they support to carry out reprisal attacks, but instead they chose to respond openly with a conventional barrage. That is not at all what most analysts were expecting, and that should make us wonder what else about the Iranian response we are failing to anticipate. So far, it appears that these latest strikes have resulted in Iraqi casualties only. That is bad news, and it shows how a U.S.-Iranian war will inevitably inflict harm on Iran’s neighbors because it will be their countries where this war takes place.

There is a narrow window for Congress to rein in the president and prevent him from making things even worse. The danger is that the president may order more strikes against Iranian targets in the next few days that could close that window. Congress must vote to cut off all funding for a war with Iran. War powers challenges are all well and good, but we know from the Yemen debate that they are inadequate in restraining Trump. Congress’ power of the purse is the only instrument at their disposal that can stop this war now. The president illegally launched this war last week without so much as consulting Congress, and Congress has to reassert its proper role in matters of war now. It is time for our representatives to reject illegal presidential wars, and they should start with the newest one.

It is important to remember that a war with Iran is entirely unnecessary, and it should have been easy to avoid. The Trump administration pursued a policy of relentless hostility towards Iran that made this war more likely with every step they took. Reneging on the JCPOA and waging economic warfare were followed by designating the IRGC as a terrorist organization and slapping gratuitous sanctions on Iranian leaders. Trump gave Iran hawks everything they wanted at virtually every stage. Ultimately, what they really wanted was war with Iran, and he has now given them that, too. This is where hard-line maximalism and an irrational obsession with harming another country predictably lead, and opponents of Trump’s Iran policy know this because we have been predicting it all along. It is imperative that we halt this war before more lives are lost and more damage is done to an already destabilized region.