Just muscular enough not to get mocked.

In 2013, after Syrian dictator Bashar Assad crossed President Obama's red line and used chemical weapons on innocent civilians, a U.S. official told the Los Angeles Times that Obama's retaliatory strike would likely be "just muscular enough not to get mocked" but not so devastating that it would elicit a response from Iran and Russia. In the end, Obama backed away from even such a small, feckless strike.

On Friday, Trump carried one out.

Trump deserves credit for acting (now twice) when Obama wouldn't. He also deserves credit for getting U.S. allies to join us when Obama couldn't. But let's be clear: Friday night's strikes were "just muscular enough not to get mocked." As a result, they did more damage to the United States' credibility on the world stage than they did to the Assad regime.

The U.S.-led strike did not hit a single airplane, airfield or delivery system, and it left Syria with chemical weapons capabilities. Even at the sites we did hit, the Syrians had plenty of time to move equipment and chemical stockpiles. There were no reported casualties on the ground, suggesting that the regime had evacuated the targets.

The Syrians know that they won. The Washington Post reports that "on the streets of Damascus, there was jubilation as government supporters realized that a more expansive assault would not materialize." Retired Gen. Jack Keane, former vice chief of staff of the Army, said the Syrians had good reason to celebrate. "The response is very weak in my judgment," he said. "It should have been decisive, it should have been consequential," he continued.

Keane said Assad made a bet with his chemical attack and won. As Keane explained, Assad wanted to take out one of the last remaining rebel strongholds in the Damascus suburb of eastern Ghouta, which was holding out despite a brutal, nonstop bombing campaign by the Russians. Assad calculated that he could use chemical weapons to crush the resistance, achieve a military victory and then absorb what he expected to be a limited U.S. strike. So, he launched his chemical strike. Hours later, the rebels capitulated. And just as Assad predicted, the U.S. response was limited.

Far from being chastened, the U.S. response will embolden Assad, Russia and Iran. And it will embolden other U.S. adversaries as well.

What lesson did North Korea likely take from Trump's weak actions in Syria? That the Trump administration is easily intimidated and risk-averse. The reason we didn't take out all of Assad's chemical weapons capability is that we were intimidated by Russia. Instead of warning the Russians to evacuate, and telling them we would not be responsible for what happened to their personnel if they failed to do so, we specifically designed our strikes to avoid even the remote possibility of provoking Moscow.

This is a major setback to the Trump administration's efforts to stop North Korea from developing the capability to threaten U.S. cities with nuclear missiles. The only way the United States can persuade North Korea to peacefully give up its pursuit of these weapons is if Kim believes Trump's threat of military force is credible. After Friday's U.S. actions in Syria, our credibility has been weakened, not enhanced.

Thiessen is a Washington Post columnist. Follow him on Twitter, @marcthiessen.