By Peter Apps WASHINGTON (Reuters) – Since Russia’s annexation of Crimea in March, NATO has been publicly refocusing on its old Cold War foe Moscow. The threats it now believes it faces, however, are distinctly different to those of the latter half of the 20th century. The West then was defending against the risk of Soviet armour pouring across the North German plain. Now, officials and experts say, it is “ambiguous warfare” that is focusing minds within NATO, the North Atlantic Treaty Organisation. Confrontations are viewed as more likely to start with cyber attacks or covert action to stir up Russian minorities in Europe’s east than from any overt aggression. So as NATO prepares for its summit on September 4 and 5 in Wales, it is having to come to grips with relatively new threats to test Article 5 of its treaty. Since NATO’s post-Cold War expansion that has meant protecting eastern members including the Baltic states.