I believe the Russian force is massed in Russia at the Latvian Border. Latvia is one of the Baltic states that Putin supposedly covets. Poland itself has no common border with Russia proper or with Latvia. However, Poland shares a border with the still-rebellious (against Moscow) western Ukraine, and Putin likely regards Poland as a corridor for NATO invasion. To get to Poland, Russia would have to go through Latvia and Lithuania, or through Belarus, which has friendly relations with Russia but is nominally neutral; or even through western Ukraine, though that's a lot of armed hostile territory. So at this point, Russia and NATO are not facing off at opposite sides of a common border unless it's Kaliningrad, an isolated Russian outpost vulnerable by land, sea and air. Russia probably would like a corridor to Kaliningrad along with eastern Poland, which it has invaded numerous times before. In a few days NATO and Russia are Trump's problem; we'll see how tough or "wimpy" Donald is.