This week, the leaders of the five Nordic nations (Denmark, Finland, Iceland, Norway, and Sweden) come to Washington for a second U.S.-Nordic Leaders Summit, similar to an event held in Sweden in 2013. Those countries’ ambassadors to the United States co-authored an article for The Huffington Post that discussed much of what is shared between the five Nordic states and the United States. However, the most noticeable message was found between the lines: rising tension with Russia. If the summit is to be successful, these six leaders must have a focused discussion on what they can do to curb further Russian aggression, including deterrence measures and greater cooperation among themselves.

Based on recent Russian actions, the timing of this summit could not be better. For the United States, it was the low flyover of the destroyer USS Donald Cook twice in the Baltic Sea and mid-air barrel roll over a RC-135 surveillance aircraft by Russian jets three weeks ago. For the Nordic states, it was Russian Foreign Minister Sergey Lavrov warning Sweden if it joined NATO Russia would be forced to increase its forces in its western district. Finland’s government made news last week when it openly published a report on alliance membership based on their concerns with their eastern neighbor. These latest actions add to a growing list of Russian activities throughout the region, including simulated invasions of Norway, Denmark, Sweden and Finland in 2015 as well as, according to NATO naval leadership, a current level of Russian submarine activity matching that of the Cold War. Therefore, a frank dialogue about Russia and what these six nations can and should do to deter further aggression should be front and center of this summit.

A Multitude of Security Layers

A discussion about possible response options requires an understanding of the security relationships between the United States and the Nordic nations. For Denmark, Norway, and Iceland, the relationship with the United States is anchored on the four being members of NATO. Denmark was one of the most active allies in the Afghanistan mission, working alongside the British in the hotly contested Helmand province. Norway is a vocal proponent of greater attention to NATO’s “High North” — the Arctic region — at a time when the United States chairs the Arctic Council. Iceland is poised to host the newest U.S. maritime patrol aircraft and hangars at Keflavik air base will receive upgrades for the P-8 Poseidon.

For Sweden and Finland, even as polls show a greater affinity for future NATO membership, their stated policy of non-alignment keeps them out of the alliance for now. Nonetheless, they both enjoy strong working relationships with the alliance, taking part in the large-scale Baltic Operations maritime exercise and other NATO-sponsored events. They each contributed to the effort in Afghanistan, demonstrating a continuing ability to work with NATO forces in real-world operations. As for their relationship with the United States, they each appreciate its value, openly stating as much in their national defense documents. U.S., Swedish, and Finnish units also train together, including a U.S. Air Force F-15 training event in Finland starting this week. Materiel transfer is also prevalent. Finland in particular uses several kinds of U.S.equipment, including the FA-18 attack aircraft and the long-range Joint Air-to-Surface Strike Missile.

As for the security relationships among the Nordics themselves, the divergent security policies of Denmark, Norway, and Iceland with NATO on one hand and non-aligned Sweden and Finland on the other makes synchronized action problematic. Add to the mix each nation’s relationship within the European Union — with Sweden, Finland, and Denmark in the Union and Norway and Iceland not — and you have an even more complicated situation. Sweden and Finland support the E.U. Common Security and Defense Policy and each contributed forces to the E.U. Nordic Battlegroup in 2015. Denmark has a formal “opt out” policy with the European Union related to security issues so as not to detract from its commitment to NATO. To further confuse matters, non-E.U. Norway actually has an “opt in” arrangement with the Union and contributed forces to the Nordic Battlegroup. To deal with this Nordic Gordian knot, the five nations formed the Nordic Defense Cooperation, or NORDEFCO, in 2009 as a way to align their views on defense-related issues and explore common areas of cooperation. This forum received more attention and focus with Russia’s annexation of Crimea in 2014 and is still active.

Deter and Assure

With the various defense relationships in mind, the United States and the Nordic states have a role to play in deterring Russia while assuring both themselves and others throughout the region. For the United States, Operation Atlantic Resolve is now in its third year, with ground forces rotating throughout the Baltic nations of Estonia, Latvia, and Lithuania as well as in Poland, Romania, Bulgaria, and Hungary. Secretary of Defense Ash Carter recently announced a $3.4 billion plus-up of the European Reassurance Initiative in fiscal year 2017 for defense-related investments in eastern European allies and upgrading pre-positioned U.S. materiel.

More needs to be done, however, to bolster deterrence in the region. While a rotational brigade of U.S. soldiers and their combat gear is a start, it fails to match the considerable scale of Russia’s military assets in the western region and only reinforces a perception that regional security is a temporary concern to the United States. While going pound-for-pound numerically is not realistic, a more permanent presence in the region should be considered as part of making Russia recalculate the cost of its current aggressive actions and providing greater assurance to our allies and partners, including the Nordic states. With that, any such move would need a commensurate communications plan directed at Moscow, with the message that a bolstered U.S. presence is in reaction to this current aggression and will be readjusted if Russian leadership returns to a more constructive relationship with its neighbors.

For the Nordic states, the force they could bring to bear is substantial. They have a combined force of approximately 84,000 active duty personnel, plus the associated mechanized equipment, combat aircraft, and naval assets. What they together would actually bring to a conflict, however, is unknown. NORDEFCO is a step in the right direction, but is still a ways from being a focused effort toward combined action for the five nations, even as the growing threat from Russia affects them all. The Nordic states should place greater emphasis toward planning with each other and in consultation with other forces like NATO, as well as bilaterally with the United States, to maximize deterrence against Moscow.

Greater Capabilities through Greater Cooperation

The Nordic nations and the United States stand to bolster European security and stability through a commensurate increase in cooperation, both in materiel and in training. While the Nordic countries absorbed the financial crisis better than most, they are not immune from the increasing costs of defense, particularly as inventories age and need to be replaced, be it Sweden’s anti-submarine capabilities or Finland’s F/A-18 fleet. Many of these nations continue to buy U.S. defense material, such as Norway’s purchase of the F-35 Lightning II. However, in order to truly maximize capabilities and justify tight procurement budgets, all governments involved must show not only how these systems can benefit the nation in question, but how they can work together on a multinational level. Increased levels of consultation during development and acquisition phases on all sides will increase system inter-operability and should be a driving philosophy for each nation’s defense posturing.

With that, the integration of technology is only as good as the integration of the personnel involved. As part of NATO, the United States enjoys deep ties with Denmark and Norway. Norwegian pilots go through U.S. flight training, for example. But standardized training as well as tactics, techniques, and procedures run the risk of leaving non-NATO partners Sweden and Finland behind. Therefore, more must be done on both sides to bridge capability gaps among the personnel involved. NATO recognized this as well, and at the Wales Summit in 2014 it declared Sweden and Finland (in addition to Japan, Australia, and Georgia) as partners under the NATO Enhanced Opportunities Program (EOP). The intent of EOP is to deepen the cooperation with key partners through staff exchanges, training events, and the like, in an effort to create better inter-operability between NATO and partner forces. How EOP has fared over the last two years is not clear beyond additional Swedish and Finnish unit participation in some exercises. Bilaterally, the United States and the Nordic nations should look toward opportunities such as joint personnel staff assignment and educational exchanges to maximize their combined force interoperability.

One cooperative gap that must be addressed is NATO’s plans for defense of the Baltic states and ambiguity over participation from Sweden and Finland. At the Wales Summit in 2014, alliance members agreed to execute reassurance measures for its eastern allies, to include updating its Readiness Action Plan (RAP) . However, beyond a host nation support agreement signed at Wales between NATO and the two partners, it is not apparent either Stockholm or Helsinki is actively involved in any RAP planning events. Many point to the political hurdles of those outside the alliance being involved in such planning. These voices should not be discounted. The military reality is any reasonable defense of the Baltic states should include a high level of Swedish and Finnish involvement, even if defensive in nature. It is therefore critical that NATO leadership overcome the political concerns and actively seek out these nations’ perspectives on specific possible scenarios.

In the past couple of weeks, Russia demonstrated aggressive behavior against U.S. forces and threatened retaliation against a Nordic nation for exploring greater security arrangements with NATO. While many topics proposed by the ambassadors in The Huffington Post are worthy of the leaders’ time, so too is a focused discussion on what Denmark, Iceland, Finland, Norway, Sweden, and the United States can do together toward promoting greater regional security and withstanding Russian pressure.

Mark Seip is currently assigned to the Navy Staff’s Operations, Plans and Strategy directorate and was previously the Navy’s Federal Executive Fellow to the Atlantic Council. For more on this topic, see his Atlantic Council issue brief, “Nordic-Baltic Security and the US Role.” The views expressed here are his own and do not reflect the Department of the Navy.

Image: Arctic Challenge 2013, U.S. Air Force photo by 1st Lt. Christopher Mesnard.