The US has a President, not a King. And the President's powers are limited, even more than the powers King John had after Magna Carta, despite Bush administration theories of a Unitary Executive. And while the Congress may have surrendered to the Executive the 4th and 5th Amendments, of the US Bill of Rights, starting WW III has not yet been a power granted to the Presidency.
Australian, Thai journalists acquitted of defaming Thai navy (AP)
from the article: Will a U.S. attack on Iran become Obama’s ‘October Surprise’?