Comment by lo_zamoyski

Please reread what I wrote.

What does it mean to betray someone? If a friend intends to murder someone and asks you to keep that secret, would telling the police be a betrayal? Would keeping it secret be an expression of loyalty?

Loyalty and betrayal cannot be understood in purely subjective terms. It must always be grounded in the objective good.

In your example, you haven't provided enough information to judge how exactly you would are betraying your country. However, if your country is doing evil things and you defend a friend from those evil things, then you aren't betraying your country. The government in question is betraying your country.