Recently, the Senate narrowly approved a resolution invoking the War Powers Act. The headlines said that it had commanded Trump to either stop fighting to the Iran War or seek congressional authorization to continue it and what seemed important was that four Republicans had joined with almost all the Democrats to pass it. Fred Kaplan tells us that it was all pretty meaningless…
The reason is that the War Powers Act, the 1973 law that slim majorities in the House and Senate invoked in a joint resolution, has rarely been taken seriously on Capitol Hill. In fact, except for the first few years after the passage of the act — which was meant to put muscle and teeth on the legislature's responsibilities under Article 1 of the Constitution — it has never been taken seriously enough to matter.
If you can't vault the paywall to read the piece at Slate, just know that it included many examples from the past of how Congress has voted that way until things reached the point of actually voting to stop a war. Basically, presidents do whatever they want to do in this area and no one stops them.