Does the army reserves Education Career Stabilization work?

I want to join the reserves, however, I am still in college. I don't want to be deployed until I finish so I told my recruiter I wanted to be stabilized through the ECS (Education Career Stabilization) program. I would have to give up half my enlistment bonus (would be $20,000 if I did not do ECS) to be protected for two years. Does the army have to respect this or could someone up the chain decide to deploy me anyway? Can anyone testify that ECS has worked for them? Someone also told me that ECS would only protect me from the operations we are currently involved in (Afghanistan and Iraq) and that if we went to war with Iran I could be "unstabalized".