See the explanation how it worked for them here: How the Boston Bombing Suspect Became a U.S. Citizen.
I'd like to know what "reasonable fear or persecution" the Tsarnaevs had. The Romeikes's is simple: in Germany they are in violation of German laws and risk that their children be taken away from them. If that is not reasonable fear, I don't know what is.
>>>I’d like to know what “reasonable fear or persecution” the Tsarnaevs had.<<<
In Tsarnaev’s case it was their home federal government persecuting them for a practice of beheading infidels and running a slave trade. It is a religious and cultural traditions and as far as we have a diversity and all cultures are equal they are worthy of asylum.
As for a German couple they are clearly a dangerous dissidents who violates their children’s rights.
No /s tag needed, it has to be a logic of such a regime.
Not sure what kind of “reasonable fear or persecution” there is when you return for holiday.