I am not saying conscription is perfect but it is definitely more acceptable to using brainwashed human clones. I am not the one arguing in black and white terms here. But yes, if, say, the borders were closed and the Senate would from one day to the other decide to start drafting, then yes, it would be slavery. Because then the Senate would've changed the social contract without giving the populace any option to accept or decline. You are also saying "when the action starts". Funny that you would do that as the action was clearly started by the Republic. The Jedi were not required to get into the "action", they willingly chose to participate.