Reuters reports Russian continues to mass troops on Ukraine border.  Last week troops numbered 20k with this week’s estimates reaching 30k.  Troops include conventional military including infantry, armor and some air support units.  Also present are militia or special forces units wearing uniforms without insignia or identifying markings.

Pavel Felgenhauer a Moscow based military analyst wrote in FP.com  that “the window of opportunity for an invasion will open during the first weeks of April and close somewhere around the middle of May.”  Factors include the coming spring but most importantly the mustering out of some 130k conscripts from the preceding year that could only be extended under a national emergency with a potential risk to morale. 

This isn’t a major issue since Russia has greatly improved the quality of its troops and moved away from a conscript base especially in its more elite units.  In reality, the window may be much larger.