In a developing story—one that could develop in very hazardous directions indeed—an American air strike on a Baghdad airport has reportedly killed Qassim Suleimani, the leader of Iran's Revolutionary Guard.

In a statement, the Pentagon claims that "the U.S. military has taken decisive defensive action to protect U.S. personal abroad" by killing Suleimani, who they say "was actively developing plans to attack American diplomats and service members in Iraq….The strike was aimed at deterring future Iranian attack plans." The air strike followed an Iranian-backed militia's involvement in an attack on America's embassy in Iraq, which in turn followed earlier U.S. air strikes.

Suleimani has been responsible for decades of overseas crimes, and he is one of the most powerful figures in Iran. While this is not yet technically a shooting war with Iran, it seems more than likely that the Iranian regime will see the assassination as an act of war inspiring retaliation.

Trump's record of, while not ending any of our ongoing Middle Eastern military adventures, at least not starting any fresh ones, might be over as of tonight. Secretary of State Michael Pompeo was already on record wanting to force Iran to change its overseas policies, and Suleimani was a prime mover in that area. Pompeo has gotten his way.

This potentially war-launching act was done without explicit congressional authorization (although the Quds forces Suleimani commanded have been under U.S. sanctions and his Revolutionary Guard had been declared a foreign terror group by the Trump administration), and it is as fraught a political act as one could imagine: triggering a new war with unknown costs in lives, materiel, and the civilizational order.

Sen. Chris Murphy (D–Ct.) tweeted his concern, asking: "did America just assassinate, without any congressional authorization, the second most powerful person in Iran, knowingly setting off a potential massive regional war?" Indeed it did.