Concerns that the conflict in Ukraine could be long and drawn out have led to fears that Europe could see a return to Cold War levels of military deployment in the East.
NATO continues to bolster its troop presence in member states bordering Ukraine, but still refuses to engage with Putin's forces directly, in an effort to avoid all-out war between the military alliance and Russia.
Former NATO official Dr Jamie Shea spoke to us about the situation.
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Thumbnail image: NATO.
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