Did President Trump just start a shooting war between the United States and Iran? As of Thursday night, it appears so — and if that's the case, it seems unlikely he is prepared for the ramifications.

The Pentagon on Thursday night confirmed the United States was behind the assassination of Maj. Gen. Qassem Soleimani, commander of Iran's Revolutionary Guards Corps, at the Baghdad International Airport. Soleimani has plenty of blood on his hands — a 2013 New Yorker profile depicted his career of "assassinating rivals, arming allies, and, for most of a decade, directing a network of militant groups that killed hundreds of Americans in Iraq" — and his death came at a time of rising tension between the U.S. and Iran that had culminated in recent days with the death of an American contractor in an attack by Iranian-backed militias, a retaliatory American strike that killed dozens of those militants, and finally protesters attacking the American embassy in Iraq.

Defense officials said Soleimani was planning to attack U.S. diplomats and service members throughout the region.

"The strike was aimed at deterring future Iranian attack plans," the Defense Department said in a statement. "The United States will continue to take all necessary action to protect our people and our interests wherever they are around the world."

Andrew Exum, a former deputy assistant secretary of defense under President Obama, put it more plainly Thursday night: "This doesn't mean war, it will not lead to war, and it doesn't risk war. None of that. It is war."

Soleimani was undoubtedly a bad man. That doesn't mean killing him was the right choice — either to protect the American people or American interests. And it is nearly impossible to trust that President Trump has taken the right action here.

The problem isn't just that Trump, who once seemed eager to avoid Middle East conflict, has escalated tensions with Iran at the precise moment he faces a legacy-tainting impeachment trial in the Senate, nor that he may think he stands to benefit electorally by confronting Iran. The problem is that he just isn't very good at this kind of stuff.

Why isn't Trump trustworthy on Iran?

1. Because the escalation is largely his fault. As my colleague David Faris pointed out in June, Trump started the journey to a confrontation with Iran by needlessly pulling the United States out of the deal that kept Iran from developing nuclear weapons — and by then imposing sanctions that caused suffering for the Iranian people and problems for that country's regime. "This needless mayhem and brinkmanship can be traced directly back to the president himself," Faris wrote, and asked: "Who incinerates a perfectly good agreement, starts issuing empty threats, and then demands that the other party come back and agree to less favorable terms?"

The Trump administration, that's who. Every moment of rising confrontation between the U.S. and Iran over the last two years can be traced back to Trump's decision to tear up the nuclear agreement. We're at this point because Trump led us here.

2. Because his process for making such decisions is unpredictable and undependable. Remember, it has only been a few months since Trump called off a planned attack on Iran at nearly the last second. That was probably the right decision, but the on-again-off-again nature of his decision-making suggested the president is guided in world-historical matters of life and death more by the vagaries of his gut than by any reasoned, principled decision-making process.

There are other problems, too, with what we know of his military decision-making process. We know, as The Atlantic reported in November, that he "disdains expertise and gets his intelligence briefings from Fox News." And he bypassed any consultation with Congress in deciding to assassinate one of Iran's senior leaders.

3. Because Americans should be skeptical every time our government puts us on the path to war. You can't take the White House's word on such matters. We invaded Iraq to prevent Saddam Hussein from using his weapons of mass destruction — weapons, it turns out, Hussein didn't have. We went to war in Vietnam based on a battle in the Gulf of Tonkin that, well, didn't really happen.

The United States government is simply untrustworthy on such matters. So when the Trump administration tells us it killed Soleimani because he "was actively developing plans to attack American diplomats and service members in Iraq and throughout the region," the right response is: "Prove it." What is the evidence of such preparations? Were they general preparations, or were attacks imminent? Why, after years of Soleimani's activities, did the United States decide now was the right time to take him out? Right now, all we have is an assertion by the Department of Defense that it did the right thing — and that is not nearly sufficient.

4. Because this moment could spiral out of control. In addition to skepticism, Iraq and Vietnam — along with the ongoing war in Afghanistan — should have taught Americans to understand that while it is easy to start wars, it isn't necessarily easy to finish them in any satisfactory fashion. Iran is a state sponsor of terrorism, which means the country's capability of responding to Soleimani's assassination ranges far beyond any "battlefield" and into civilian communities around the world. It seems likely Americans are now more — not less — endangered by Iran than they were a week ago.

This is a dangerous moment. Lives have been lost. It seems likely that even more people, on both sides of the conflict, will die soon — unless, somehow, cooler heads prevail. Americans want to rally behind their president in such a moment. But President Trump hasn't proved that he deserves the benefit of the doubt. So this isn't a moment for rallying — it is a time, instead, for healthy skepticism.