Protestors didn't speed the end of Vietnam
We were all sick of Vietnam. That war would have ended with or without protestors because the total will of the people had turned against it. The "silent" majority that Robert has so little respect for were fed up with the political, refusal to win, conduct of the war. The protestors were a just a nuisance then as they are now.
Protest has been an effective civil rights tool and protest can be effective in some instances but they were but a minor factor in the Vietnam war.
I agree that it our duty to speak out, as we are doing here but there are many ways to speak out.