ISTANBUL Spanish Prime Minister Pedro Sanchez on Thursday called NATO's proposal of increasing defense spending by 5% "irrational." In a letter addressed to NATO Secretary-General Mark Rutte, Sanchez refused to commit to 5% increase in defense spending and called it "irrational and counterproductive," according to Spanish news agency EFE. He suggested a more "flexible" formula for the proposal to be approved at the NATO summit in The Hague next week and supported Spain's exclusion from the 5%