President Trump’s cruise missile strike on Syria last Thursday night is being thoroughly misread at home and abroad. That’s entirely understandable, because the president apparently has no coherent strategy or policy that he’s trying to implement.

There was no attack on America that preceded the missile strike, necessitating a military response. The Assad regime’s forces was against Syrian civilians. It employed a chemical weapon – probably Sarin – and left about 70 people dead, including a number of children. President Trump’s action was taken as a direct result of his emotional, visceral reaction to the horrors of war for which he was unprepared to see. Pictures of the casualties shocked him to his core.

On Wednesday, reacting to the Assad regime’s attack, Mr. Trump seemed almost unbelieving of the brutality of war. His voice shook when he said, “When you kill innocent children, innocent babies, babies, little babies, with a chemical gas that is so lethal – people were shocked to hear what gas it was. That crosses many, many lines, beyond a red line, many, many lines.”

Military options were prepared and presented to the president. He chose the easiest one, an attack that didn’t risk the lives of American soldiers or sailors. About 63 hours after the Assad regime’s attack, 60 Tomahawk cruise missiles were launched by two American destroyers targeting the Shayrat airbase near Homs. About 20 Syrian aircraft were destroyed and perhaps a dozen casualties were inflicted.

The attack wasn’t decisive: It didn’t kill Assad or topple his regime. Was it a reversal of policy? That remains unclear.

About an hour after the missiles hit the Syrian air base, Mr. Trump said, “It is in this vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons.”

Well, no. There is a very important distinction here. Yes, we have an interest in preventing the spread or use of chemical weapons but not one that qualifies as a vital national security interest.

A vital national security interest of the United States is an interest that has to be defended by military force against any aggression. A chemical weapons attack against Syrian civilians, terrible as it may be, isn’t against a vital U.S. national security interest.

The fact that we have hundreds of troops in Syria to fight ISIS necessitates a military response to any aggression – chemical attack or otherwise – against them. Deterring an attack on our troops may also have been one of the president’s thoughts in ordering our missile attack, but that’s not the reason he gave in justifying our action.

So where does that leave Mr. Trump’s often-announced policy of destroying ISIS? Does it now include forcing regime change in Syria?

In March, Secretary of State Tillerson said Assad’s future should be decided by the Syrian people. Faint hope there was of that, given the strong support of Assad by both Putin’s Russia and Ayatollah Khamenei’s Iran. Now, Mr. Trump and his team are saying that Assad has to go. Or are they?

On Sunday, Tillerson gave voice to the president’s incoherence. Tillerson said on Face the Nation that “we believe that the first priority is the defeat of ISIS.” He also seemed to declare victory over ISIS and then think better of it.

Tillerson said, “By defeating ISIS and removing their caliphate from their control, we’ve now eliminated at least or minimized a particular threat not just to the United States, but to the whole stability in the region.… Once the ISIS threat has been reduced or eliminated, I think we can turn our attention directly to stabilizing the situation in Syria.” And why we need to do that, he didn’t say.

Adding to the confusion, Tillerson said he was still hoping for a solution to the Syria war, which meant bringing Assad, Russia, Iran (and who knows who else) to the bargaining table.

“Clearly, that requires the participation of the regime with the support of their allies,” Tillerson said. He added, “and we’re hopeful that Russia will choose to play a constructive role in supporting ceasefires through their own Astana talks, but also, ultimately, through Geneva.” He went on to imply that “safe zones” for civilians could be established by the Russians. Why they would do that, he didn’t say.

Which is just what we heard from the Obama administration for the past five years.

Through the campaign, Mr. Trump was saying that it would be good for us to partner with Russia to fight ISIS in Syria. There never was a serious hope of that. After last week’s missile strike on the Shayrat air base, Russia cancelled its agreement with us that allowed “de-confliction” of air operations in Syria to prevent U.S. and Russian aircraft from colliding with or shooting at each other.

Also in response to our attack, the Russians announced that they were going to strengthen Syria’s air defense systems.

Mr. Trump finally seems to understand that Russia isn’t going to cooperate with us against ISIS or in any other way. On Friday, U.N. Ambassador Nikki Haley blasted the Russians, asking, “How many more children have to die before Russia cares?” That was obviously a rhetorical question. On Sunday, National Security Advisor Lt. Gen. H.R. McMaster said Russia was supporting a “murderous” regime in Syria.

But how does Mr. Trump intend to deal with Russia (which is supplying the Taliban with arms and other support)? We don’t know and probably neither does he.

So what comes next for ISIS and Syria? Though he has indicated otherwise, it’s entirely likely that Mr. Trump’s missile strike was a one-off event.

As Mr. Trump probably has discovered, his options are severely limited. The Russians and Iranians dominate the Syrian battlespace and will prevent us from removing Assad.

As I’ve written before, Russia has established permanent naval and air bases in Syria. Their foothold will expand as they defend the Assad regime against the rebels we support. Those who casually say that we should establish “no-fly zones,” as we had in Iraq before the 2003 invasion, either don’t know or don’t care that we’d have to take on Russian and possibly Iranian air forces to do so.

Given the fact that we don’t have a vital national security interest in Syria, we shouldn’t want to take on those forces. And given the horrific state of our airpower – both Navy and Air Force – we probably can’t. Even if Mr. Trump wanted to, we lack the ability to sustain a big fight in the Middle East or anywhere else. (Too important a subject to cover here, suffice it to say that 70 percent of the Marines’ F/A-18s are incapable of combat operations as are 30 percent of all USAF aircraft. The Navy isn’t in better shape.)

It’s arguable whether the defeat of ISIS is a vital national security interest, but its actions in Syria, Iraq, Afghanistan (where ISIS killed a U.S. soldier last week) and in about two dozen other countries qualifies it as a serious threat. But that doesn’t differentiate it from other terrorist networks such as al-Qaida. If we are going to “utterly destroy” ISIS, as Mr. Trump said he’d do, he’s going to have to destroy it in Syria as well as Iraq, Afghanistan, and about two dozen other countries. It’s evident that he has no strategy to do so.

Mr. Trump is not prepared, by education or experience, to deal with his lack of coherence on war strategy and foreign policy. Even if he understands that problem, he apparently is content to wait to solve it until after his White House team and Cabinet cease fighting among themselves for position and influence.

Mr. Trump has been in office for almost 80 days. Many of his policy options have already been negated by our enemies and more will be with every passing day.

Last Thursday, the same day that Mr. Trump ordered the Syria strike, was the 100th anniversary of America’s entry into World War One. We were latecomers, the war having begun almost three years before.

In 1916, during some of the worst fighting of the war, Winston Churchill said, “It is no use saying, ‘We are doing our best.’ You have got to succeed in doing what is necessary.” Mr. Trump may feel that he and his team are doing their best, but it’s necessary for them to create a coherent strategy and start to pursue it.