foreign nations would know what the US does and doesn't know, and how to exploit it.
How does it help "foreign nations" to know how much the U.S. is or is not spying on its own citizens? How can foreign nations "exploit" a lack of domestic spying? How can foreign nations even "exploit" knowledge about international spying by the U.S. government?
What a backwards comment. Ed Snowden didn't release this information to harm the U.S., he did it to inform U.S. citizens about what their tax dollars were buying without their knowledge. This is stuff citizens should have a right to know.
If World War III were going on, you might have a point about keeping spying ops secret. But in peacetime (and this is peacetime, notwithstanding a couple of US-lead skirmishes), there should be less spying and much more transparency.