@Jack Tschitt: The US is missing a drone, and Iran claims to have a drone. There is no reason to doubt that they have a drone (an especially advanced one at that) of ours in their possession. At any rate, I wouldn't call any "attack" to bring the drone down a cyber attack necessarily--such would imply the drone's programming was tampered with (such would have to be a previous action, or else foreign and malicious programming would have to be inserted while the drone was in flight), which seems rather impossible--if anything, Iran somehow managed to sabotage the drone's communication link to its controller (its tether), or else the drone's power. I chose to dub such a thing an "electronic" attack, because such seems like something that is feasibly possible with forces that could be so utilized and already rule the minds of science fiction and thriller writers. (An electromagnetic pulse is a devastating effect a nuclear explosion has, by the way. A nuclear weapon can potentially devastate another country while not killing many [if any] of its citizens.)
But again, it's charitable to assume that Iran is capable of that.
@Jack Tschitt & @Tempa!: It is sensible to assume/demand that the US not allow sensitive, advanced technology to fall into the hands of anyone, especially enemies and antagonists. Drones employed in sensitive areas should have some self-destruction protocol--or, at the least, sensitive elements should have such protocols. (Y'know, it'd be both amusing and ironic if the Iranians obtained a supposedly sensitive drone that in fact contained little sensitive design information--but that'd be charitable, to assume the US was so clever.) At any rate, a tamper-triggered self-destruction protocol does indeed make sense. It'd also be smart to increase any doubt about such elements.
@Tempa! & @Mijzelffan: China could live without the US, and the US could live without China. One shouldn't make out a country's way of life, politics, and economy to be embedded into the country. The US might not be so profligate if it didn't have such a lender as China (alternatively, it possibly could have such a lender even if China didn't exist), but it would appreciate not having a powerful and antagonistic rival in the region and world in general. China, meanwhile, would be a #2-ish (granted, #2 stinks) power in the world were there simply no United States. At any rate, scenarios in which things simply don't exist don't make much sense, and aren't the best things to waste your time thinking about. Scenarios in which things leave existence or change phase make more sense, as the way in which a thing happens (and not just a happened thing) also determines outcomes. There's also the vacuum phenomenon: nature abhors a vacuum. There'd be a power vacuum, for one, if either of the countries didn't exist, as well as such things as influential and geographic and security vacuums: who would possess China's access to the rare earth elements located there? what would Japan's security plan be if there were no US--would it then pursue or have pursued earlier its own nuclear weapons capabilities? would whatever country/countries that occupied the place of the US be open markets to China? etc. etc.
@TheKnittingno.: You hope China, who is developing a stealth aircraft of their own (in that case a fighter jet), gains access to the drone? Perhaps you're just a technology enthusiast (that would be charitable), but China getting a hand on such a thing would in all likelihood neutralize the capability of US drones against China and various of its allies (which many it could have, given its economic clout), if not other nations as well. We should also note that drones decrease the human risk and cost of war, which would mean that in conflict, the US, a beneficent power as far as nations go, would suffer many more losses in war, while China, a power not beneficent, an antagonizing and ambitious power (seeking to dominate and close off the region), would be empowered and possibly emboldened.
We should also note that it is vaunted American capabilities that deter war from nation-states.