No. The President can only make recommendations to Congress to declare an Act of War; both sides of Congress must agree in accord ( majority vote ) for War to be declared.
Given your scenario, doubts hold ANY member of Congress would vote against going to war with China. Many would say such would NEVER happen---but then again, we never thought Japan would bomb us like they did, either.
The one thing about war today I disagree with is the implementation of "political correctness" military troops IN WAR conditions MUST be bound by in combat situations; such tends to KILL our troops more than SAVE them.
There is NO honor in war today; we have to get as---if not MORE---low down and dirty as our enemies.