The problems were obvious in the Navy just after Obama began destroying it (2008). The cancer spread quickly.
A brutal loss in a wargaming exercise last October convinced the Vice Chairman of the Joint Chiefs Gen. John Hyten to scrap the joint warfighting concept that had guided U.S. military operations for decades.
“Without overstating the issue, it failed miserably. An aggressive red team that had been studying the United States for the last 20 years just ran rings around us. They knew exactly what we're going to do before we did it,”--DefenseOne quoted at AmThink
You can read more at the link.
Trump, by the way, was no help at all. Throwing money at armed forces led by morons will not make those forces superior. Hugging Generals who can't discipline their own children--much less their subordinate officers--won't do the trick.
A mass resignation of all flag officers might be in order here.