Well, last time I checked, the only country that had any nukes that could get anywhere near us was Russia,

and here's what Russia thinks of China link

So what would really happen, outside of the Armageddon dream world so many people live in for some reason, here's what would happen worse case:

China declares war, begins amassing a monolithic military, poors their very impressive resources (they're the 4th richest country in the world, after the U.S., Japan, and Germany) into weapons. They appeal to the UN and every nation for allies. There would be a worldwide uproar, but at the end of the day, China would get only a few minor players on their side like N. Korea and Iran. Everyone else decides to stay on the sideline initially, there would be talks of sanctions, but the major powers would abandon this, as they would realize their country would go broke before the U.S.

Meanwhile the U.S. would amass it's even more monolithic resources toward fighting off the most populous country in the world. Initially no one would be on our side worth mentioning. But as the gears of war turned, and it became obvious our military superiority would overcome China's population advantage, you would see countries who have long been suspicious of China, see an opportunity for gain.

To China's surprise, Russia would most likely side with us once again, and actively. Also, once the bombs start flying, and we have stealths enroute, long time allies who morally object to our bombing, would lend us a tentative hand, these include Canada and the UK (both of which are far more powerful than any of China's allies.)

Maybe a hundred thousand U.S. soldiers would find an early grave. China would be littered with millions upon millions of corpses.

Everything would eventually go on as normal.

But, now the world would have lost all respect for the U.S. Every country would be ready for the day we randomly set off a nuke, and our pool of goodwill would be empty. Eventually we would lose our status as the super power of the world. And the next time something like that happened, there would be no reason for anyone to aid us, we would no longer have overwhelming military superiority, and we would likely lose that time.

Best case:

China blusters, but realizes there's no point in going to war, and demands reparations. We give reparations based on world pressure and threats of trade embargoes.

And like with the last scenario; now the world would have lost all respect for the U.S. Every country would be ready for the day we randomly set off a nuke, and our pool of goodwill would be empty. Eventually we would lose our status as the super power of the world. And the next time something like that happened, there would be no reason for anyone to aid us, we would no longer have overwhelming military superiority, and we would likely lose that time.

I believe, nay I know that if we were to send a nuclear warhead to China that it would start a nuclear war. The reason being is that all of China and all of her allies who have nuclear weapons would most likely fire them at us. And lets face it, most of China's allies do in fact have nuclear or biological weapons, and if they decided not to retaliate it would just send us into another cold war.

http://www.endofworld.net/

You must watch the Movie Dr. Strangelove if you really want to know. This is a movie by Stanley Kubrick, who is a genius! It's a comedy and in black in white but it hits during the soviet union and Cuban missile crisis. Great film and will answer your question to an extent no one here can ;)

well firstly notting the projectory of nuclear rockets is highly ineffective so when we prepared to fire russia in particular would arm and wait for us to fire or they may fire early leading to the same results as "ze end of ze world" found on youtube leaving australia saying "wtf mate"

If USA threw a nuke to china there will be 45 nukes from over 45 countries crashing into USA.

And then world war 3 will start.

alot of you are assuming that countries would join in against china, and these supposed enemies would come out of the dark and attack china, but youre also forgeting about the hidden enemies of america. most americans see themselves as do gooders, but this is not always the view around the world. they might think that would be a good opportunity to attack america, while america is busy fighting another war. in fact, maybe many countries are sick of being bullied by america, and are afraid to speak up, and just waiting for the right opportunity to do it. american allies might decide to attack america and put their money on the other team. with america out of the picture, the european union can possibly take the place as a world power. in fact, if china and usa were to go to war, the eu would have a lot to benefit. you see all these scenarios play out in a lot of gangster films where the assistant to the boss decides to join the side of his enemy in order to take the position of the boss, because he is second in line. you also see these kinds of scenarios play out in prison movies, where inmates are waiting for new bad ass to come into the prison, and then the old inmates will plot against the current alpha male with the new challenger, but while the current alpha male is still operating, inmates still recognise him as boss and do all the necesary ass kissing.

i also dont think its impossible for america to nuke china. america can, as it always does, make up some story about china being a threat, and decide to attack it, not because it really is a threat but because america wants to dominate more business in the world, and china is in the way of american domination. america might also decide to attack china because it does not want to repay a debt, so it will make up a story and make it justifiable.

Don't just send one nuke. Blast the whole country to high heavens and be done with it.

Mutant chinese babies with extra arms who will be used to increase the production rates in sweatshops.

Well, China would definitely retaliate, so, WWIII would happen.

China would find every way to get us back just as we fought to get them back when they bombed pearl harbor.

Come on lets do it lol jk it won't hurt anyone it will just say don't mess with the U.S.