Remember, that in the (first) American Revolution, only 3% of the able bodied ever lifted a rifle and fired upon the British, while only about a third of the people fully supported independence.
I don't think things have changed that much since the 1770s, but I will say that I believe better than 10% would stand and fight today.
I try to keep all that in mind when discussing this subject online.
Bump for acknowledgement.