U.S. President Donald Trump has spent a lot of time in the courts, so he must be familiar with the legal concept of "cui bono" — "who benefits?" When a crime is committed, the likeliest culprit is the person who benefited from the deed. But he certainly did not apply that principle when deciding to attack a Syrian government air base with 59 cruise missiles early Friday morning.

The attack against Shayrat air base, the first U.S. military action against Syrian President Bashar Assad's regime in six years of civil war, was allegedly a retaliation for a poison gas attack on the rebel-held town of Khan Sheikhoun three days before that Trump blamed on the Syrian regime. But who stood to benefit from the chemical attack in the first place?

There was absolutely no direct military advantage to be derived from killing 80 civilians with poison gas in Khan Sheikhoun. The town, located in territory controlled by al- Qaida in Idlib province, is not near any front line and is of no military significance. The one useful thing that the gas attack might produce, with an impulsive new president in the White House, was an American attack on the Syrian regime.