First of all neither I nor you live in the United States, so we have no idea what is actually good for them, but we can give our opinion on the debate and which candidate would be better for the world in general.
I dont think even you could say that the two wars the US and my country are fighting at this moment in time in Afghanitan and in Iraq are working at all, the only thing both of these wars are doing are radicalising more and more of those people they were supposed to be liberating because they do not see the forces stationed there as liberators anymore they only see them as an occuping force, who are only there to drain the natural resorces of their native land and let as many people die as possible with little regard for anything else but themselves. McCain does not want to leave this war until the US has "won" and to not allow this to become another Vietnam, but what he cannot see is that, there is no winning this war, it is already over. The only way to win this war would be to nuke the entire middle east. And as thats not going to happen the only option left is to talk to these people and use diplomacy before the gun comes out, because thats the only way anything is ever going to get done, threats of more violence are doing nothing, Iran is radicalising more because of the threats thrown at them by Isreal and its security blanket the US, wouldnt you go on the defense if you were threatend with air strikes and invasions, I would. Yes their president on behalf of the Iotolas (spelling???) says some really crazy things, (Isreal has as much of a right to be their as Palastine does IMO but some of the tactics used by Israel are totally disgusting and deserve investigations but due to it being so close to the US nothing happens) but the threats have got to stop from both sides not just Iran, and sitting down and talking is the first step towards that. This will never happen under McCain and the world especially the middle eat will continue to progress as it has over the past 8 years, which means more attacks killing innocent civilians and soldiers.