Its mincing words a bit, but an attack targeting drug cartel assets wouldn't necessarily be viewed as a war with Mexico. It could lead to that for sure, and the Mexican government could declare it an act of war, but we did just see the US literally invade a foreign country and arrest their sitting leader without war being declared on either side.
We declared war on drugs and on terror, maybe AIDs and Covid as well? Though you're right, we haven't declared war on another state since WWII despite being in multiple wars over that time.
I assumed when you wrote "war being declared" you meant in Constitutional sense which reserves to Congress the power to declare war.
Not in the metaphorical "war on poverty" sort of way.
FWIW, examples in addition to Maduro are Aguinaldo (Philippines), Noriega (Panama), Hussein (Iraq), and Aristide (Haiti).
(Technically speaking, the US didn't recognize Philippine independence so didn't consider Aguinaldo to be its president, but instead a rightful cession from the Kingdom of Spain due to the Treaty of Paris, which ended the Spanish–American War, where the US had made a formal declaration of war.)
(Also, the US says Aristide's departure was voluntary.)
