...in the final scene of the final episode of series 2.

Spoiler ahead alert...

Post apocalyptic scene in a Washington DC bar between some politician and journalist.
Turns out there was an "event" that led to a full scale nuclear retaliation/cataclysm that caused the destruction of most human life on earth.
That "event"...well, it was a Iranian "Dirty Bomb" dropped on Washington DC.
The politician guy jokes that his uncle always hated Iran so he now has even more reason to.

Fer fucks sake...how pathetic!