The Putin regime has built a conventional military machine that is capable of posing a significant threat to its immediate European neighbors, including members of NATO. According to the Defense Intelligence Agency's 2017 report, Russian Military Power:

Although Russia's military strategy is officially defensive, the Russian Ground Troops' fundamental principle of land warfare is violent, sustained, and deep offensive action, just as it was during the Soviet era. Mechanized and armored formations supported by aviation and artillery are to seize the initiative at the outset of hostilities, penetrate the enemy's defenses, and drive deeply and decisively into the enemy's rear area.

The strategic implications of these capabilities for Moscow were described by General Phillip Breedlove, former NATO Supreme Allied Commander Europe, as far back as 2014: “They are absolutely able to bring great force to a position of readiness. That is something that we have to think about: What does that mean geo-strategically that we now have a nation that can produce this ready force and now has demonstrated that it will use that ready force to go across a sovereign boundary?”

Russian conventional forces are capable of conducting a rapid, high-intensity campaign against the states on its immediate Western periphery. Latvia, Lithuania and Estonia – all NATO members – are particularly vulnerable to a conventional surprise attack. The RAND Corporation has intensively analyzed the military balance in the Baltic region. The conclusions of this effort are sobering:

As currently postured, NATO cannot successfully defend the territory of its most exposed members. Across multiple games using a wide range of expert participants in and out of uniform playing both sides, the longest it has taken Russian forces to reach the outskirts of the Estonian and/or Latvian capitals of Tallinn and Riga, respectively, is 60 hours. Such a rapid defeat would leave NATO with a limited number of options, all bad.

Moscow understands that it is at a serious disadvantage if confronted by the united economic and military power of the Western Alliance. Nor can it hope to win a protracted conflict. As a study by the Carnegie Endowment observed:

Given the disparity in overall military and economic power, full-scale, prolonged, and conventional conflict with NATO would be likely to entail unsustainable losses for Russia. Any military options to challenge the West must, therefore, count on a swift resolution, exploiting Russia's local superiority before the full but distant potential of the West is brought to bear.

To deter Russia from attempting to use its large and well-equipped ground forces either to intimidate its neighbors to the West or to conduct a lightning war against the Baltics, Poland, Ukraine or Romania, NATO must have a robust conventional capability deployed in Eastern Europe. The Obama Administration, which had withdrawn all U.S. heavy armored forces from Europe, realized its mistake following Russia’s invasion of Crimea and Eastern Ukraine. Reversing course, it created the European Reassurance Initiative which was meant to fund efforts to buttress NATO’s defenses. This included prepositioning sets of heavy equipment in Eastern Europe, the rotational deployment of an Armored Brigade Combat Team (ABCT) and a series of ever-growing NATO exercises involving relatively large numbers of ground forces.

Given the growing Russian conventional threat to its eastern neighbors, including NATO members, more needs to be done. In particular, the U.S. and its NATO allies must deploy sufficient ground power to deter, if possible, and counter, if necessary, any Russian attempt at a “lightning strike” conventional offensive against these vulnerable countries.

What is required are heavy forces including armored brigades, aviation formations, and long-range fires units, positioned in Eastern Europe. To be credible and to draw additional Alliance forces eastward, the central pillar of these new deployments must be from the U.S. Army. Additional NATO heavy forces would need to follow. Given the disparity in the balance of forward deployed Russian and NATO forces and Moscow’s advantages in shorter lines of communications, NATO forces must be deployed close to the Alliance’s eastern frontier if they are going to have any credible chance of halting a Russian offensive.

Months ago, the United States began negotiating with Poland over the deployment of additional U.S. forces in the latter. The Polish government was hoping for the permanent deployment of a full U.S. armored division. Warsaw offered several locations where troops and equipment could be housed in addition to some $2 billion to defray the costs of operating a permanent base.

Apparently, the United States and Poland agreed for the time being to deploy a more limited set of forces deployment than that which will be necessary to confidently deter Russia. The core of such a deployment would be elements of a full U.S. armored division, including an ABCT, elements of a division headquarters and some critical enablers. The ABCT will not be permanently stationed in Poland. Instead, units from the continental United States will be continually rotated forward. With an additional ABCT based on prepositioned vehicles and equipment and the airborne and Stryker brigades already forward deployed in Europe, the Army could form a capable heavy division.

The decision to deploy key elements of an armored division to Poland is a step in the right direction. But it is only the first step. The next one should be to deploy a second rotational ABCT simultaneously to Poland. This would allow the U.S. Army to exercise a full division. Such a move would also be a strong signal to Russia that any conventional aggression against NATO’s eastern flank will be met with decisive force. Ultimately, if Russia continues its provocative behaviors towards NATO, it may be necessary to deploy U.S. forces forward permanently, up to a full heavy corps.