i think we'd kill them both. china outmans us, but we have superior armed forces. of course with our economy in the pooper, it does cast some doubt.

The US has the most technologically advanced and powerful army in the world. Yes the Chinese outnumber us but you tell me how 300,000,000 untrained soldiers fare against 50,000,000 highly trained soldiers with complete naval and air control. Iran sucks no questions asked we own them. Oh and about the Korea Vietnam thing the US did not lose that war militarily but politically without the full commitment of the people you cannot win and that is what happened. But if you take world war II into account we kicked butt because the people were behind the military and if China attacked us they would quote "Awaken the Sleeping Giant". That would definitely not be good for those little people. One more thing China has to feed all those soldiers explain to me where they get enough food for them when we blockade their harbors.

We would definitely own on Iran, but China would be tougher. Still I think we could take them with us buying their stuff the economy becomes worse than ours.

all we would have to do is set off an atomic bomb on their capital and their other populated cities and we would kick their butts!!!!!! muhahahahaah

Assuming we don't have to deal with some pansy ass bitches telling us that we can't do this and we can't do that, then yes, we can win.

There would be a word for US vs Iran and China. It is called slaughter. China VS America would be just like Japan VS America, a war for the Pacific. The US navy (in tonnage) is the biggest navy in the world, even bigger than the 17 countries behind it, all added together. We also have superior planes, the F-22 is stealth so the Chinese planes could not lock missiles onto it. The Chinese use Russian MiG29s which would be decimated because the F22's missiles could lock onto it.

Iran would be pretty easy as well, while our Navy is over in the Pacific, our Army would be in Iran kicking ass. Iran is not that powerful compared to our Capitalist Might! =)

All this is presuming no nukes are involved*

It really depends on what you would consider victory. The US could not take over either country or anything like that, but the US could easily win a strictly military war against either of these countries. Neither of these countries could realistically threaten the US mainland. Also, neither country has the technology to defend themselves effectively against a shock and awe type of attack that the US is capable of delivering.

The US could definitely win if we have allies against China. Even if they did attempt to nuke us, they really only have like 30 operational. We have 4000. They would never do that if they were smart. Of course, they could hack our computers, which we rely on heavily. Iran would just be a joke. We would march in and march out.

Can we use our nukes? Can I push the button? You know, the big red one ;)

when you bring WMD's into it, china has nukes and Iran has at least a dirty bomb(even if it's just a diaper full of poo), but doesn't U.S.A. have more nukes than both?

Iran we could take, currently. A decade ago, however, if Iran and Iraq had simultaneously switched their oil sales to the Euro, they might have toppled the dollar. Note that this is exactly why they got put on Bush's "Axis of Evil." But now it's become clear Iran isn't willing to back up its tough talk, and probably isn't able.

China, however... they have this habit lately of showing just how powerful they are. Their nuclear sub pops up in the middle of our naval maneuvers, just to thumb their nose at us. I think there was something about them hacking into our government's database, which is no small feat. And on multiple occasions they've made public their strategies to cripple us with lightning speed.

And then there's the economy-- currently, China could possibly crash our economy at great sacrifice to its own. They own so much of our debt that if they were to call it all in, our only option would be to completely devalue our currency to pay it off. Both countries would likely be poor, but guess which one is more viable in a crash? Then again, China is erasing this advantage by becoming just as dependent on petrol as us.

Now some context: if China really were that powerful, they wouldn't have to make themselves LOOK strong. Unless they've got something even more devious up their sleeves, it belies China as the 21st Century's preeminent superposeur.

Right now, I am confident that the USA would win. Now, 10 years from now could be different story.