(CNN) -- From wars in Ukraine and Afghanistan to the fast-spreading spectre of ISIS in the Middle East, it's no wonder that this week's NATO summit in Wales is being called "the most important gathering of NATO leaders in more than a decade." NATO leaders arriving in Cardiff will have a host of issues to deal with, so what should we expect? In short, we should see a return to NATO's core mission of facing a re-emerging security threat from the east. Russian President Vladimir Putin's push in to Ukraine has the 28-nation alliance focused on action -- and that goes double for NATO's new members in the east, including Estonia, Latvia, Lithuania and Poland.
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NATO summit is called "the most important gathering of NATO leaders in more than a decade"
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NATO may return to core mission of facing a re-emerging security threat from the east
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Russian President Putin's push in to Ukraine has the 28-nation alliance focused on action
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As NATO looks to its future, it wants to build on its past
And @placeholder, NATO's biggest overseas commitment of troops, is in flux, so adjustments are required there as combat troops prepare to depart at the end of the year.