The Constitution didn't create a regime like the Dutch Republic of the early 18th Century, where military decisions had to be sent back to parliament for approval.
The Constitution forces a choice on Congress: either (a) cut the defense budget and reduce the military's size and avoid or repudiate treaty obligations that entangle the US in military affairs all over the globe; or, (b) react to perceived threats and interests by funding a huge military and intel apparatus that has the effect of putting the President in the driver's seat.
All this, "Congress needs to approve" twaddle is a product of political wrangling over the Vietnam War and has no legal precedent behind it.
Only congress can declare war. What the US is doing are clearly acts of war. But hey, you won’t have to fight it. So who cares, right?
That twaddle you mention is in the constitution. Only Congress has the power to declare war.