Nicola Sturgeon has expressed "doubt and scepticism" over the effectiveness of US air strikes in Syria.
Scotland's First Minister said she was concerned attacks would increase "uncertainty and unpredictability" in the Syrian conflict.
Ms Sturgeon, who has just completed a five-day official visit to the US, backed an intensification of efforts to broker peace and called on countries including the UK to do more to help those fleeing the conflict.
She said: "My doubt and my scepticism about simply dropping bombs is that it doesn't necessarily take us one single inch closer to that peaceful outcome."
She added: "What I understand is the instinct to do something in the face of the quite horrific chemical attack carried out by the Assad regime earlier this week.
"That regime is completely beyond the pale."
Boris Johnson looks "daft" and is in "deep political trouble" after pulling out of a meeting with the Russians, Alex Salmond has said.
The defence secretary condemned Vladimir Putin's Kremlin for its role in Bashar Assad's suspected chemical weapons attack on his own people.
The leading critic of the Trump administration has told ITV News the US and its allies must build on the president's justified airstrikes.