The 라도 particle means if nothing else, this much, and 쓰다 covers two different verbs spelled alike. Writing is the commoner one here: you should at least have written a handwritten letter, let us at least sign a pledge, at least writing a card for each person, at least keeping a diary. Using is the other, as in shall we use this one instead, and in the remark that India and Israel at least share English.