Sentence:  The annual spring meeting has given an impetus in three main directions : more , deeper , and more timely political consultation within the alliance , the use of the Organization for Economic Cooperation and Development ( when ratified ) as a method of coordinating aid to the underdeveloped countries , and the need for <WSD>strengthening</WSD> conventional forces as well as the maintenance of the nuclear deterrent . 
Meaning of the word marked with <WSD> tags:  make strong or stronger