Second is the fact that Trump himself in 2013 urged Obama not to enforce that red line. To wit:
But even more conspicuous than that, the statement takes a harsh tone toward the Obama administration without saying what the Trump administration will do differently. The applicable Trump policy here, in fact, appears even less stringent than Obama's was: It's leaving Assad in power in the name of fighting the Islamic State (ISIS) first.
As recently as last week, both Secretary of State Rex Tillerson and U.S. Ambassador to the United Nations Nikki Haley both signaled that Assad would be left alone.
“Are we going to sit there and focus on getting him out? No,” Haley said.
Tillerson said during a trip to Turkey, meanwhile, that he thought the “longer-term status of President Assad will be decided by the Syrian people.”
Obama set a red line and then didn't live up to it; the Trump administration's policy is apparently to talk tough without dictating any specific policies — except that Obama's policies were wrong (even though Trump agreed with them in the end).
The White House, of course, explains that it doesn't want to tip off the enemy before any action is taken. “I think the president has made it clear in the past, and will reiterate that today, that he is not here to telegraph what we're going to do,” press secretary Sean Spicer said earlier Tuesday.
That's a great excuse for not having a real strategy, which the Trump administration doesn't seem to have.