Your government doesn't have to be any more trustworthy in general than the US'. From the legal side, say your government has basically the same legal regime as the US: local citizens'/residents' data on the local cloud have some legal and/or constitutional protection from the local government, but non-resident aliens on the local cloud have none. If you leave your data on the local cloud it has some legal protection, while if you put it on the US cloud it has none. (Really, none as soon as the US government decides to go after you specifically. (IANAL.) It seems the US doesn't even have to state a pretext of "counter-terrorism", "national security" or anything else to take your data under FISA 702. http://www.govtrack.us/congress/bills/110/hr6304/text )
Now, in many countries even local citizens in the local cloud have no legal protection from the state, or legal protections notionally exist but don't really impede the security services at all. (By all accounts the PRC is one of these.) But this is where motivation comes in to it. Many people outside the US have good reason to fear their own government more than the US'. In that case you could be better off trusting your data to the US cloud, even if it means you're trading away some real legal protections in exchange for getting getting your data out of the hands of a local government which is motivated to work around those protections to get at you. If your data also has no real legal protection locally then it's an easier choice. The problem is that some people - for example, non-US companies with interesting commercial data and US competitors - may in fact have more reason to fear the US government than their own.
I can't stop the local government from looking at my data if it wants to. I can stop the US government from looking at it. Wich is more trustworth isn't a relevant question.
> I can't stop the local government from looking at my data if it wants to. I can stop the US government from looking at it.
I doubt that.
US government intelligence gathering within the US is being reported on right now and controversial because their are strong expectations and at least some legal restrictions that suggest that such surveillance is exceptional.
But if you think keeping your data overseas means that the foreign intelligence gathering apparatus of the US government isn't going to get at it, then you may have failed to think things through clearly.
Now, in many countries even local citizens in the local cloud have no legal protection from the state, or legal protections notionally exist but don't really impede the security services at all. (By all accounts the PRC is one of these.) But this is where motivation comes in to it. Many people outside the US have good reason to fear their own government more than the US'. In that case you could be better off trusting your data to the US cloud, even if it means you're trading away some real legal protections in exchange for getting getting your data out of the hands of a local government which is motivated to work around those protections to get at you. If your data also has no real legal protection locally then it's an easier choice. The problem is that some people - for example, non-US companies with interesting commercial data and US competitors - may in fact have more reason to fear the US government than their own.