And I believe that it is unConstitutional for them to do so. There is no power in the Constitution for them to engage in war without declaring it. I previously pointed out the line from the Declaration of Independence which I believe is relevant:
"...a decent respect to the opinions of mankind requires that they should declare the causes which impel them ..."
Great Britain was engaging in many wars and managing an empire at the time of our Revolution. Many of the objections raised by our Founders to the behavior of King George centered around the fact that the need to conduct war was used as a pretext for violating human rights.
Soldiers were quartered in homes, people were stolen off the streets by press gangs and forced to do duty at sea, ruinous taxes were passed to cover the cost of distant wars. Paul Revere did not ride through the night shouting "The British are coming". He shouted "The Regulars are coming", referring to the Regular Army.
The provision in the Constitution giving Congress the power to declare war was to prevent an imperial president from doing so himself and creating just the pseudo-war situation in which we now find ourselves. If Congress has not declared war but has just passed a joint resolution instead, then there is no war. There is just military action by a President outside the controls dictated by the Constitution.
"Journal of the House of Representatives of the United States
December 8, 1801
TH. JEFFERSON.
... Unauthorized by the Constitution, without the sanction of Congress, to go beyond the line of defence, the vessel, being disabled from committing further hostilities, was liberated, with its crew. The Legislature will doubtless consider whether, by authorizing measures of offence also, they will place our force on an equal footing with that of its adversaries."
He got that authority from congress, and fought a Constitutional war against the pirates.