The Roman philosopher Cicero recounted how King Dionysius answered a courtier, Damocles, who thought that ruling a realm was merely pleasure and leisure. In response, King Dionysius offered Damocles to switch places. However, King Dionysius ordered that a large sword be hung precariously above Damocles’ head, suspended by a single hair from a horse’s tail. Realizing the danger that came with ruling a kingdom, Damocles gave up his envy of the king.

Estonia, Latvia, and Lithuania are under looming danger from a Russian “Sword of Damocles” today. Evidence of this growing peril includes the Kremlin’s increasingly harsh rhetoric towards NATO, the aggressive and often reckless behavior of Russian military aircraft in the Baltic Sea region, and the increase of massive Russian military exercises in the region. This Russian “Sword of Damocles” was demonstrated in the cyber-attack against Estonia in 2007, the war against Georgia in 2008, the annexation of Crimea in 2014, and the ongoing war against Ukraine. Additionally, there is Moscow’s information operations campaign directed at Russian speakers living in NATO nations.

Russian president Vladimir Putin is responsible for this unpleasant turn in Moscow’s relationship with NATO. His grand strategy is to reassert Russian influence in the region and to make Russia a dominant player in international affairs. To achieve this, Putin needs to diminish the credibility of NATO, especially in the Baltic nations. There are two military approaches that Putin can pursue to push NATO out of the Baltics. The first is a direct attack, and the second is via hybrid warfare tactics.

This “unthinkable option” of a direct attack on Estonia, Latvia, and Lithuania would be a high-risk move that could only come if American leadership is weak, and NATO’s commitment to its Baltic allies is diminished. In such a gamble, Russian forces would seek to seal off land, air and sea access to the Baltic Region within 36 to 48 hours. The narrow Suwalki Gap, just 60 miles wide, is where Russian troops would sever land access to the Baltic nations from Poland and the rest of NATO. Once the land route is cut, Russian anti-aircraft and anti-shipping assets would make it too risky for US and other NATO forces to arrive.

The more likely Russian strategy, however, would rely on ambiguity. This would take the form of fomenting a “local” (exported from Moscow) ethnic Russian separatist movement similar to what was witnessed in Ukraine. This would occur in an area with a high Russian-speaking population in either Estonia or Latvia. These would not be the little green men of Crimea, which were quickly identified as Russian forces. In the Baltics, Russian special forces could appear as locals seeking independence for the “discrimination” that they suffer from Estonians or Latvians. Moscow’s goal would be to destabilize the region while denying responsibility. The purpose of this ambiguity is to cause NATO to delay as it determines whether the crisis was foreign or domestic.

In the time that NATO deliberated, Russia would have space for a low risk move to destroy the alliance. Moscow would send a large force to the borders of Estonia, Latvia, and Lithuania to intimidate the alliance and to provide covert support to their separatist movement. As security deteriorates and the local population suffers, Putin would announce a humanitarian mission to end the distress. Of course, Moscow would pledge that the army would be withdrawn from the disputed area once security is restored. Without firing a shot, NATO could be undermined, with a simple act of occupying a modest piece of Baltic land without war. The brilliance of this strategy of ambiguity is that should NATO respond rapidly, Putin could deny involvement.

How should NATO respond to such a risk? There are concerted steps that NATO and the United States can take. Frontline, vulnerable allies such as the Baltic states should be armed with offensive capabilities that give them a modest ability to strike Russian bases, transportation hubs, and airfields. Acquiring mid to long-range weapons could make threatening these nations less appetizing to Moscow. If attacked, these offensive weapon systems could wreak havoc on Russian command and control nodes, transportation hubs and disrupt the movement of Russian forces. This would provide the Baltic nations a credible military capability and strengthen deterrence capabilities.

The US can help. It should station more military assets in the region, to complement the US Army’s campaign of making “30,000 American Soldiers look like 300,000” in Europe. The genius of such a concept is to blend the Active Army with the Army National Guard and Army Reserve to support the European Theater. Exercises conducted in the region must be expanded in size and scope. Part of this expansion should be called “Deploy Forces to the Baltics.” Using the Return Forces to Germany concept (an annual exercise to deploy American forces from the United States to Europe) during the Cold War, the goal is to allow units to fly soldiers into the region and use the American equipment already staged there. This reduces the arrival time of “over the horizon” forces considerably.

Finally, the key to forward defense of NATO is to permanently station American and other NATO forces in Estonia, Latvia, and Lithuania. This force should be a three-brigade element, one in each nation. Estonia should have a mechanized American Brigade Combat Team, Latvia a regional Baltic Brigade that should include forces from Sweden and Finland (if they are willing to participate as non-NATO partners). The brigade in Lithuania should be a multi-national NATO force permanently stationed in the Suwalki Gap. Keeping this gap open is imperative lest the Baltic states are cut off from the rest of NATO. The purpose of these three brigades is to provide both an equitable level of deterrence/assurance, while also providing sufficient forces to secure key infrastructure (i.e. airports, sea ports) to facilitate the arrival of additional NATO forces.

This three-brigade model for the Baltic nations borrows from the Berlin Brigade concept from the Cold War. Although the American, British and French Brigades stationed in West Berlin could not stop a Soviet invasion, they guaranteed that three powerful nations would defend Germany if attacked. The same logic would work in the Baltic states. Deploying more NATO forces there would mean that the cost of meddling in the Baltics would be too high for Moscow to contemplate.

The emerging Russian “strategy of ambiguity” is a direct threat to the NATO Alliance. Yet, it can be defeated now with resolve, and a modest forward deployment of American at NATO forces in the region. A rotational brigade is a start, but not the final answer. NATO leaders have the opportunity during next month’s Warsaw Summit to take concerted action to deter Russian aggression against the Baltic nations. The first step is to station NATO forces “permanently” in the region. There is a Russian “Sword of Damocles” hanging over the Baltic Region, yet the risk can be blunted by the physical commitment of NATO land power to Estonia, Latvia and Lithuania. NATO has the opportunity this summer to show strength and solidarity against a rising threat to the peace and prosperity of the European Continent and the world.