Critics said such decisions could be considered a war crime. The President was not dissuaded.
"If they attack again, which I would strongly advise them not to do, we will hit them harder than they have ever been hit before!" President Trump tweeted, adding that a U.S. response might be 'in a disproportionate manner.'
The President's Sunday tweets stirred even more questions following his Saturday vow to target 52 different Iranian sites - some important to Iran and "Iranian Culture" - as Mr. Trump vowed Iran "WILL BE HIT VERY FAST AND VERY HARD."
In Congress, Democrats accused the President of trying to start a full-scale war with Iran, as they questioned whether he had any concrete plan other than bellicose rhetoric aimed at the Tehran regime.
"President Trump seems hell bent on starting another endless war in the Middle East," said Senate Democratic Leader Charles Schumer. "He does not have the authority to do so."
"Only Congress can restrain an unhinged President," said Sen. Tim Kaine (D-VA), who introduced a resolution under the War Powers Act to prevent any further hostilities aimed at Iran.
"Tough talk isn’t a strategy," said Rep. Seth Moulton (D-MA).
On Sunday in Baghdad, the Iraqi Parliament voiced its support for a plan to force the U.S. to withdraw its military forces, a move which drew a sharp verbal rebuke - and an economic threat - from President Trump.
"We will charge them sanctions like they’ve never seen before ever," the President told reporters aboard Air Force One, as he threatened 'very big sanctions on Iraq,' hours after the vote of the Iraqi Parliament.
Meanwhile, the U.S. this weekend said American forces in Iraq would no longer conduct raids against Islamic State forces in the region - instead concentrating on force protection at bases which the Iraqi government evidently wants the U.S. to vacate.