Well the US made a sovereign country president plane land with a threat they will shoot it down then grabbed out the president of a sovereign country from his plane and searched the plane for Snowden. There are probably 3 countries in the world the US wouldn’t do this to: China, Russia and Israel. So no, Snowden didn’t have much choice.
Talking about steam, steam-powered things are 2 thousand years old at least and we still use the technology when we crack atoms to make energy.