The Hunt for Black October

What first sounded like something straight out of a Tom Clancy novel is turning out to be Moscow’s first serious test of Western resolve since the invasion of Crimea earlier this year. While details are patchy and the situation is still unfolding, three separate credible eyewitness accounts and a photo showing a dark structure descending into the shallow waters of the Baltic Sea seem to confirm the presence of a foreign submarine or mini-sub some 30 miles from Stockholm. If so, this would be a major escalation of tensions in the Baltic Sea region.

Adding to the mystery are other reports of a North Sea-bound Russian container ship sailing under a Liberian flag hovering outside Swedish territorial waters. Defense analysts have speculated that this might be the submarine’s mother ship. In response to these chilling developments, the Swedish military has launched one of its biggest military operations in decades, involving some 200 men, a number of stealth ships, minesweepers, and helicopters to locate the suspected sub and its crew. Sweden has five submarines of its own, down from 12 in the late 1990s.

While the Swedish government has not yet confirmed exactly who is behind this "foreign underwater activity" (as the incident is officially labeled), the obvious suspect is Moscow. If so, this would not be the first time that a Russian submarine has been spotted in Swedish waters. During the heyday of the Cold War in the 1960s to 1980s, the waters off Sweden’s coast were a favorite playground for Soviet submarine activities. The most notorious case was the "Whiskey on rocks incident" in October 1981, when a nuclear-armed Soviet submarine became stranded in Swedish waters near one of the country’s most important naval bases. After a 10-day standoff, the situation was eventually resolved peacefully and the submarine tugged back into international waters, where it was handed over to the Soviet navy.

Today the threat does not come from the Soviet Union but from Vladimir Putin’s resurgent and revanchist Russia. Though the events this weekend are exceptional in that they represent the kind of bold intrusion into Swedish territory that has not occurred in years, the incursion is far from unique. Along with the rest of the Baltic Sea region, Sweden has witnessed an uptick in hostile Russian behavior in the past few years as Russia has increased its aggressive maneuvers — on land, air, sea, and in cyberspace.

In 2007, a diplomatic crisis broke out between Estonia and the Kremlin. The crisis emerged after the Estonian parliament voted to relocate a Soviet-era statue from the center of Tallinn to a nearby military cemetery. In response, Russia launched a massive cyberattack that lasted for weeks and targeted the websites of Estonia’s government, banks, and media. In 2008, Russia went to war against Georgia, claiming that its military actions were necessary in order to "protect" the Russian-speaking minority in the country — a very similar claim to the justification used in the incursions into Crimea and eastern Ukraine this year.

Since the war in Georgia, Russia has been conducting an extensive military buildup. In 2013 alone, the Russian military budget grew by 26 percent. Most of the modernization efforts have been focused on the Western Military District, which is based in St. Petersburg and includes the Russian enclave Kaliningrad, and the Northern Fleet, which is based on the Barents Sea. Moscow’s improved military capability and aggressive ambitions have been demonstrated through a series of military exercises. In 2009, Russia performed Zapad, a military exercise ending with a simulation of a nuclear attack against Warsaw. On Easter in 2013, Russia simulated another bombing of a neighboring country, this time Sweden being the target.

Since the annexation of Crimea in March and the invasion of eastern Ukraine shortly thereafter, the aggressive Russian behavior has intensified in the Nordic-Baltic Sea region. Many of Russia’s aggressions include airspace intrusions. On May 21, Russian aircraft briefly breached Finnish airspace, causing Finland to scramble its fighter jets. Several weeks later, Russian jets entered Latvian airspace four times in two hours. Toward the end of August, Russia breached Finnish airspace four times in one week. And on Sept. 17, the most serious Russian incursion of Swedish airspace took place, when two Russian jets briefly passed by close to the Swedish island of Öland, prompting Sweden to scramble several JAS Gripen jets to intercept the intruders. Foreign Minister Carl Bildt called the latter incident "the most serious aerial incursion" into Swedish airspace he had seen during his eight-year tenure.

The growing Russian hostility has also been obvious at sea. On two occasions in August and September, Russian military ships intercepted a Finnish vessel carrying Swedish research personnel. The underwater incursion outside Stockholm this weekend follows the same pattern, but takes it one step further by moving the hostility out of international waters and into Swedish territory.

Besides traditional military intimidations, the threat of Russian hybrid warfare has grown, notably in the Baltic states. A large part of this consists of information warfare, or direct propaganda. In Latvia, for instance, many of the Russian-speaking media outlets have been bought by Russian companies, often with close ties to the Kremlin. The aim, according to defense researchers such as those at the Swedish Defense Research Agency, is to stir up discontent among the large Russian-speaking minority. Other threats against the Baltic countries have been more direct. During a conference in Riga in September, a Russian Foreign Ministry official warned that discrimination against Russian speakers would have "far-reaching, unfortunate consequences" for the Baltic countries.

The list of Russian transgressions and intimidations in the region goes on. But the point is this: Russia is increasing its efforts in seeking to influence the entire Nordic-Baltic Sea region.

For NATO, this development is worrisome. Several experts focusing on Nordic-Baltic security believe the Baltic countries are the next region Putin might try to destabilize. Estonia, Latvia, and Lithuania are therefore now monitoring the situation in Sweden closely. Latvia’s foreign minister, Edgars Rinkevics, tweeted that the events in Sweden "may become a game changer of the security in the whole Baltic Sea region."

What can NATO do to keep the game from being changed in Putin’s favor? The alliance’s credibility lies in its ability to uphold Article 5 of its charter, which establishes a collective defense among the allies: An attack on one NATO country is to be considered as an attack on the alliance as a whole. While Sweden and Finland are not NATO members and thus not subject to Article 5, the nearby Baltic states are. Putin’s adventurism off Sweden’s coast is an implicit threat to those countries, too. Defending the Baltic states is about more than just reassuring allies. It’s ultimately about maintaining the functioning of the entire trans-Atlantic alliance.

During a visit to Estonia earlier this fall, President Barack Obama declared that "the defense of Tallinn and Riga and Vilnius is just as important as the defense of Berlin and Paris and London." Yet the United States and NATO have still to prove that there is real substance behind these words. The NATO summit in Wales last month was a step in the right direction. At the summit, NATO created a military ground presence in the Baltic countries on a temporary rotational basis. The alliance also established a new, 4,000-strong "spearhead force" that can be activated within 48 hours in the event of an attack against a NATO member.

This is a good start, but more has to be done to adequately defend the region. In particular, NATO has to find means to address the hybrid warfare that the Kremlin has mastered to such effect. Establishing a permanent military presence in the Baltic countries consisting of special forces focused on unconventional threats could be one way of doing so. Ultimately, the latest submarine incident in Swedish waters serves as yet another reminder of the deteriorating security situation in the Baltic Sea region. Even if Sweden and Finland are not members of the alliance, developments in these waters are important to the United States and NATO, and will require more attention going forward.