Montenegro on Serbian citizenship law

When does a sovereign nation, before they enact laws, obtain permission from another government?
Since Montenegro now has a new language per their new Constitution, what language do they use when the Serbian and Montenegrin governments communicate? Do they need an interpreter?

Way to go Serbia! This will surely help our brothers in the other republics to continue to be a Serb and not get assimilated by propaganda.

Montenegreen government is rushing to condemn this. I don't understand why?
Besides, many Croats (from Boka bay), Bosniaks (from Sandjak) or Albanians from Ulcinj have already taken citizenship in Croatia, Bosnia or Kosovo.
Why would Sebs be exempt from this and have their Montenegro citizenship revoked, when nobody else didn't?

This is a terrible law that Serbia felt the need to pass without any negotiations with neighbohring countries.

It would kind of help Kosovar-Serbs, except Kosova wouldn't revoke their (soon2b) Kosovar Passport, but instead, require them to have a visa to enter Kosova. The visa regime would take around 8-10 months to insure no criminal background, etc etc.
Also the visas may have a maximum stay of 3-4 months, all thanks to Serbia.

Maybe Serbian Kosovars will benefit from this law in the future when Kosova becomes indipendent. Dual citizenship is something really nice. Gives you double opportunities to live and work.

This is a terrible law that Serbia felt the need to pass without any negotiations with neighbohring countries.

It would kind of help Kosovar-Serbs, except Kosova wouldn't revoke their (soon2b) Kosovar Passport, but instead, require them to have a visa to enter Kosova. The visa regime would take around 8-10 months to insure no criminal background, etc etc.
Also the visas may have a maximum stay of 3-4 months, all thanks to Serbia.

Maybe Serbian Kosovars will benefit from this law in the future when Kosova becomes indipendent. Dual citizenship is something really nice. Gives you double opportunities to live and work.

Way to go Serbia! This will surely help our brothers in the other republics to continue to be a Serb and not get assimilated by propaganda.

When does a sovereign nation, before they enact laws, obtain permission from another government?
Since Montenegro now has a new language per their new Constitution, what language do they use when the Serbian and Montenegrin governments communicate? Do they need an interpreter?

Montenegreen government is rushing to condemn this. I don't understand why?
Besides, many Croats (from Boka bay), Bosniaks (from Sandjak) or Albanians from Ulcinj have already taken citizenship in Croatia, Bosnia or Kosovo.
Why would Sebs be exempt from this and have their Montenegro citizenship revoked, when nobody else didn't?