PIC duties
Putting aside both government's statements , the PIC / Captain of the aircraft has certain duties and responsibilities under the ANO .
Perhaps both governments can now propose to change the fundamentals of the ANO .I think not .
I was faced with something similar on the ground at an Italian airport , no diversion was involved .The Italian authorities made all sorts of threats after an evacuation was made .
If you are the PIC / Captain , then your responsibility is to your passengers and crew . There can be no arguement on that . It would be a sorry day in aviation , when you hand over total control of safety of your aircraft to security services and / or politicians . That said , of course , you take on board all the info available to you .
Therefore I think it is a mute point , the respective airlines contacting government departments . it has nothing to do with them . If you feel an evacuation is necessary , then so be it .
No steps , no problems , blow the slides , and be very prepared to support your actions , again under the ANO .