Trump's hands are definitely tied, and I think peoples' opinions regarding the situation are directly tied to whether or not you still trust Trump. If you do trust him at this point, you were and probably are pretty heavily bias towards him, and still believe he is a man that gets things done. If you do not trust him, or have an negative bias, then you probably don't trust him to put his shoes on the right feet at this point, let alone deftly handle an international, nuclear arms discussion.
When people were getting upset at Obama for not doing enough after the Red Line incident, people who liked and trusted him assumed that he had done his due diligence and made an informed decision that it was better not to follow up. People who didn't like Obama thought that he was showing a lot of weakness and completely botched the entire thing.
Personally, I think Obama always did the work required to make as informed a decision as possible, whether you agreed with it or not, whether it was blatantly liberal or not. I don't see how anyone could still believe that Trump is putting in the time and effort to understand the subtleties of these situations. Information doesn't just magically transfer from the office to the person in it. You have to work your ass off, and there hasn't been one sign that signals Trump has even attempted to understand these issues.