Ask anyone who died on Grenada whether it be the few hapless Cubans we capped in the process or one of the few US personnell. Was it a war or a police action? Did the sitting US President need to take the time under the circumstances to ask congress and approve funding? Of course not.
Did LBJ know or realize or even begin to think that the little police action he and his predecessors got us into (albeit with the best intentions like 99.9 of all our actions) would balloon into what it became? Nah.
No sitting president is obligated to "get funding for" or ask the congress before he commits US military people to action in what he sees and his advisers see as necessary to fulfill the oath of office that he has taken.
Can you imagine the time that would be lost if we had to go "ask permission" of the group of weenies we typically have in the congress and the senate and or ask them for funding to defend ourselves from either internal or external threats.? ! LOL.
Nope.... presidents just need to go ahead and "bombs away" and then listen to the other side whine later. Even in the most 100% objectively justifiable use of any armed force in our defense he or she would still see a strong degree of opposition in this day and age. (code pink being the big political power they are would sway people across the country LOL)
So when thinking about a need to prosecute war for the common good and when that action is seen as needed ASAP no president should ever need to ask first or have his action subjected to constitutional scrutiny. If that were the case we might as well fold our tent.
Let the bombs fly and listen to the code pink crybabies afterwards. Thats the lay of the land in our current polarized environment.
Any sitting president whether he be Dem or Repub or Liberwhatever must fulfill his oath of office and make hard decisions that might lead to (gasp) criticism. Up to an including the use of Armed forces on an expedited basis.
Anything else would be suicide.