Blitzkrieg

What is the optimal way to play this strategy?

I find with the -2 defence, it is hard to impossible to cap my opponent.. Am I suppose to focus on taking all his extra countries first, before i cap him? or am I doing something wrong in my approch to capping my opponent?

P.S. i dont wana hear about how bad of a strategy it is. Plz give advice on how to play it, and not tell me to play a different strategy..