President Donald Trump hasn't been in the White House for 100 days, but he's already done an apparent 'U'-turn on a number of his key campaign promises.
As a candidate, Trump dismissed NATO as "obsolete," saying the post-World War II organisation wasn't focused on combating the growing threat from terrorism.
And he complained that too many members weren't paying their fair share toward defence.
But after a meeting with NATO Secretary General Jens Stoltenberg the US President struck an entirely different tone.
He now says it is "a bulwark of international peace and security."
So what's prompted the switch and how will Russia respond?
In Washington DC: Richard Weitz, who's Director of the Center for Political-Military Analysis at the Hudson Institute.
In Moscow: Ivan Timofeev, Director of Programs at the Russian International Affairs Council.
In Tallinn: Urmas Paet, who's the former Estonian Foreign Minister and is a Member of the European Parliament.