Complex sentence: Russia's actions increased tensions in nearby countries historically within its sphere of influence, particularly the Baltic and Moldova; all have large Russian-speaking populations, and Russian troops are stationed in the breakaway Moldovan territory of Transnistria.
Split into simpler sentences: Russia's actions increased tensions in nearby countries historically within its sphere of influence, particularly the Baltic and Moldova. All have large Russian-speaking populations, and Russian troops are stationed in the breakaway Moldovan territory of Transnistria.