The Japanese hit our peacetime Navy and Army 78 years ago at Pearl Harbor, bringing America into World War II. We should not forget how we were taken by surprise.
After we won the Cold War, we got used to fighting enemies that we had to go around the globe to fight, but who really couldn't wage war on us here. Terror, sure. But nothing that could really dent our military superiority.
But now we have entered a world of great power competition. We should no longer assume our home ports are safe harbors.
No, really, try to remember that:
So stop doing this. An enemy may calculate the military balance and conclude they shouldn't risk taking us on. Unless, they think, somehow in the opening hours of a war they start that they can take down our power a notch. And then the calculations look a little better!
It's all nice and convenient until an enemy figures it can count on this situation and figures out how to exploit it. That picture doesn't look as impressive--for us--when smoke is billowing out of hulls settling into the water with keels resting on the bottom. But if the enemy sends up a camera drone to film in the minutes after the attack, it will look pretty good for them.
The Pearl Harbor attack didn't, ultimately, work out well for the Japanese when they figured those thing out in 1941. But we paid a price to make sure it didn't turn out well for the Japanese.
UPDATE: Related. By all means guard against a Pearl Harbor in space. But don't forget about guarding against a Pearl Harbor in our Navy port.
And remember that Iran is under American sanctions now just as Japan was under American sanctions back then. So check ammo and double the watch in CENTCOM.