Latvia's decision last week to declare Russian-born journalist and blogger Leonid Ragozin persona non grata has drawn attention to a broader trend: Russians who once presented themselves as opponents of Vladimir Putin are now accused of echoing Kremlin narratives.

Some now live in Europe, taking advantage of the

Mr. President,

I write these words without diplomatic formulas or ceremonial language. I write simply, from one human being to another, and from one president to another — two men who understand that there are moments in history when decisions determine not only the fate of nations, but the fate