The president as COmmander in Chief has broad latitude here. This is a long standing precedent.
True.
But it was not always thus, or, at least, it was not commonplace, and the 'usual' road to war.
Perhaps it is time to strip the President of his Undeclared War Powers, in some way, so as to force a Declaration of War from Congress?
Then again, aren't there circumstances under which there is no time to convene Congress, and, consequently, Congress has delegated some of its powers to the Executive?
The Congressional Declaration of War was crafted in another century, with older technologies and modes of travel in mind.
Perhaps there is some way to find a middle ground?
Give the President X-number-of-days of carte blanche authority to engage in warfare, after which he must go to Congress, for asset to continue, or to shut it down?
Ooooops... wait... we already HAVE something like that, don't we?
Makes sense.
When Congress is not in session, and you've got an incoming ICBM that is gonna hit in 20 minutes, there's no time to call Congress back into session and let 'em vote on it.
Perhaps there is some way to 'tweak' what we already have, to give Congress more control, while preserving a PRACTICAL freedom of action for the POTUS?
Or, perhaps, what we have now is just fine... it's just that we haven't done a very good job of entrusting it to worthies, over the past few decades?