So the risks are different. If China does mass surveillance on us citizens, then what are the potential downsides? China can do targeted influence campaigns in the us, China can do targeted espionage in the us.

The harms that come from this are against us national security as a whole, the harms are not to individuals and civil liberties. Even if both China and US governments are bad actors, then the fact that China is spying on Americans will not affect Americans civil liberties.

On the other hand if the United States does mass surveillance on Americans, then that can be used by bad actor administrations to suppress dissent, throw people who disagree in prison, suppress speech. Essentially the government has the targeted ability to suppress civil liberties.

So it is very different, because the incentives and potential downsides are different. Similar with companies. Google does not have the ability to lock you up for your Google search, the federal government does (if you are American).

It's the same with Nato/allies, it's not about the country, it's about the spying governments ability and incentives to act on the information.

We don't want the stasi, but imagine a world where the stasi instead had millions of files on Scottish people. What is the worst the stasi could do? What is the worst they would be realistically incentivised to do?

It's not so much about morals as about the power that the governments have over the people they are spying on. I think it's wrong for the US gov to spy on Canadian citizens living outside the US. But the fact is the US gov has no power over those Canadian citizens outside the US. Whereas the US gov has a great deal of authority over US citizens, or foreign nationals living on US soil, and therefore the information gathered through mass surveillance becomes a much more dangerous weapon.