[pierrem15]

Under international law, a state of war can exist whether or not Congress acts, whether by the the US being attacked or by US attacking.

In the current war in Ukraine, the US is a cobelligerent, not a belligerent.

A Congressional declaration activates the treason clause, so that opposition to the war past a certain point or trading with the enemy becomes treason.

No one ever considered this to be a legal restriction on the President's use of the armed forces before Vietnam, but Presidents normally had to obtain Congressional action simply because US forces were too small for any substantial engagement. But they were freely used in many smaller engagements like Haiti, gunboats in China, Central America, etc., without Congressional authorization.

[JoSixChip]

the US is a cobelligerent, not a belligerent

Providing targeting intelligence, supplying the weapons and training to act on that intelligence is a belligerent act. And international law means nothing. We are a constitutional republic, not a globalist nation. At least not yet.

[DesertRhino]

“Under international law, a state of war can exist whether or not Congress acts,“

The US Constitution trumps any so called “international law.”

[mylife]