When In Doubt, Wag the Dog

The American missile attack on Syria will have little practical effect.

• The Americans warned the Russians well ahead of time, and the Russians in turn warned the Syrians. So Assad was able to evacuate his personnel and equipment ahead of the attack. Beyond some destroyed buildings, nothing of value was damaged.
• Pledging no further action, the attack will have no preventive effect.
• Trump will see a small uptick in his poll numbers. This is because Americans love it when their president blows shit up. This bump will likely be short lived.
• Trump's base in the alt-right, already angered by the demotion of their hero Steve Bannon and Trump's failure on any of their other issues, hate the Syria attack because it violated their isolationist creed. They are viewing this missile attack as another betrayal. Which it is.

Continuing my Night of the Long Knives analogy, the attack on Syria was intended to tell the Wehrmacht and Abwehr (Pentagon and NSA) that Trump is turning his back on his radical followers and that in the future he will support the military/industrial complex. Trump can resume his radical agenda after the militarist neocons have been co-opted.

Update:  Syria reacted to the US missile attack by bombing the town they had previously gassed. Thus showing the missile attack was sound and fury signifying nothing.