What did Donald Trump do today?

He unintentionally delayed, and possibly reduced, the sentencing of convicted Army deserter Bowe Bergdahl.

Sgt. Bergdahl, a former captive of the Taliban, pleaded guilty to charges of desertion and misbehavior before the enemy last week. He was expected to be sentenced today, but comments made in the meantime by Trump have thrown a wrench into the proceedings. During the campaign, Trump used Bergdahl to attack President Obama for having approved a prisoner exchange to recover him--though at the time the nature of Bergdahl's disappearance and capture were unclear. Trump called him a "dirty rotten traitor," using the word "traitor" on at least 45 separate occasions, and suggested that he should be executed by firing squad or dropped from a plane. 

A military judge previously rejected Bergdahl's claims that those comments made by candidate Trump constituted "undue command interference." But after Bergdahl's plea, Trump was again asked for his opinion. He replied that he couldn't comment on an ongoing case--"but I think people have heard my comments in the past."

Today, Col. Jeffrey Nance--the same judge who denied Bergdahl's original motions regarding Trump's campaign statements--halted proceedings to consider the question of whether President Trump's reference to his prior determination of guilt and calls for execution counted as an unlawful exercise of influence on what are supposed to be independent trials. Col. Nance has great latitude in sentencing, and was sharply critical of the negative impact that Trump's comments could have on the public's faith in the military justice system. He told prosecutors that this could be a factor in his sentencing.

Why does this matter?

• A president who cannot control himself from blurting out threats, even when they work against his own interests, is too undisciplined to lead the United States military.