With a voice on my first, the OP doesn't have me; he lives in a foreign country.
With a raise on my second, the OP simply cannot do me; I am so wild.
With a block on my fourth, the OP has simply done me; so will the answerer.
With a retraction on my fourth, the OP maybe will do me; he wants to be a topologist.
What am I?
It's a 4-letter word.