I think if the citizens stays complacent of its government actions than they should be equally liable. I have always tried to distinguish difference between not liking or disagreeing with the government of USA and having the same attitude towards the citizens of USA. But you can only drag it for so long.
What will it take for you go to the street against your government? Governments of other countries have fallen for much less crime, yet the american government gets away with killing thousands of people and violating national and international laws under false pretence. And the USA citizens gets to wash their hands from any responsibility by simply arguing that the government did it.
Having military base itself is nothing wrong, nor is sharing intelligence in itself.
But the german citizen would be responsible if their government is engaged in so called pre-emptive war, under the pretense of terrorism and engaged in multi-year war with thousands of deaths and the citizens didn't even lift a finger.
Similarly if the german government is engaged in country-wide surveillance program under the pretense of security to control and possibly suppress its citizen, then yes the citizen is absolutely responsible if they sit on their ass for years and do nothing about it.
What will it take for you go to the street against your government? Governments of other countries have fallen for much less crime, yet the american government gets away with killing thousands of people and violating national and international laws under false pretence. And the USA citizens gets to wash their hands from any responsibility by simply arguing that the government did it.