cooperation & conflict in transatlantic defence and security structure

the both atlantic side relations from the ancient time had been faced with too much challenge but the continuing of this relation is due to the common political and economical interests. the upper atlantic and the two organizations (nato, eu) still exist to gain the essential goals and the political and security connection which are boosting with the economical integration at the same time. but we cannot neglect the disintegration of the two atlantic sides and the approach of the us and the eu in facing with some serious treats such as terrorism which had created a big gap on the strategic and military designing of two sides. in fact there is another gap in the matter of defending investment which could be managed. the first gap caused the increasing of deference in military capability between the eu and the us in fulfilling the common military operations either in europe or elsewhere. although the military cooperation in nato is very important, the us doesn’t make any contribution with its european allies in nato to seek the national security strategy. now concerning the new security challenged in 21 century, the main question is, whether the security and defense relation of two atlantic side countries is moving towards cooperation or conflict?