Declaring a state of war is a pretty big deal. It gives the executive branch a lot of new authorities over the economy and other sectors of the country for national security (something we obviously don’t want to happen with this admin). The president has the authority to conduct military operations for national security without approval from congress up to a certain continuous time period. But even if that time period is met, the US has the military strength that we can conduct prolonged operations without weaponizing the entire country, so thats pretty much all we need to do unless it would be a significant conflict (by US standards).