Donald Trump’s lack of knowledge about issues that have real effect on our nation was on display again, Wednesday night.

At a candidates’ forum, the GOP nominee and reality TV star took a whack at defining how he would serve as commander-in-chief over the nation’s military.

As the Republican presidential nominee slammed the foreign policy of President Barack Obama and former Secretary of State Hillary Clinton, he also targeted the top officers who have served under them, who are not political appointees and have defined terms of appointment.

“Under the leadership of Barack Obama and Hillary Clinton, I think the generals have been reduced to rubble,” Trump said at the NBC News “Commander in Chief Forum,” where he and his opponent, Clinton, appeared. “They have been reduced to a point where it’s embarrassing to our country.”

Trump had once stated that he knew more about ISIS than our military generals. In the forum, he suggested that he would remove them from their positions.

Apparently, Trump still doesn’t get that he can’t run the presidency like his TV show. There’s no “You’re fired!” when dealing with our military. At least, not based on presidential fiat. They can be replaced for reasons of misconduct or failure to do their duties, but not because they don’t say nice things about him on Twitter.

The top commanders serve a set term of about four years. Most of those positions have recently turned over, so whoever is in now will likely be in for several years into the next administration.

Marine Gen. Joseph Dunsford is the current Joint Chiefs chairman, and serves as the top military advisor to the president.

Dunford has gone out of his way to urge all troops to stay out of politics this year, citing concerns that the military could be politicized. Some top officers worry privately that if they are perceived to have political leanings one way or the other a President Trump could fire them, making it very difficult for the top brass to regain its reputation for impartiality.

In other words, a President Trump would give our military concerns that are extracurricular to the mounting troubles they already face, in a harsh and increasingly dangerous world.