Originally posted by no1marauder
He took no such oath. Here's the oath he did take:
I do solemnly swear (or affirm) that I will faithfully execute the office of President of the United States, and will to the best of my ability, preserve, protect, and defend the Constitution of the United States.
Nothing in the Constitution is consistent with the President unilaterally deciding to oust another country's leader.
We'll see whether he does a unilateral ousting and whether it is ruled by official (constitutional) means that the office is faithfully executed by that event. Until then it is a matter of conjecture. Faithful execution of office and defense of the constitution are the stated interests.