In yet another indication of the return of great power politics and the cratering U.S.-Russia relationship, the Defense Department announced last week the return of the historic and venerable 2nd Fleet, which has traditionally guarded the Atlantic approaches to the continental U.S.

The fleet was disestablished in 2011 in an attempt to save money and free up funding for new ship construction. That decision proved shortsighted. The revamped command will have nearly 300 officers and enlisted men and women, and will take on responsibility for training the Atlantic Fleet and, more importantly, conducting real-world operations to track potentially hostile vessels approaching the U.S. coasts.

What does the return of the 2nd Fleet say about America’s maritime strategy and relations with a resurgent Russia? First and foremost, it shows a needed response to new geographic imperatives. For three centuries, the U.S. has enjoyed the benefits of the vast ocean buffer between it and the querulous states of Europe. During World Wars I and II, the U.S. and its allies had to fight hard to gain full “sea control” over the North Atlantic. Germany used undersea warfare very effectively to try to cut off the vital “sea lanes of communication” (i.e., shipping routes) that enabled the free movement of troops and supplies to beleaguered European allies.

During the Cold War, the two vast fleets — U.S. and Soviet — played extended games of cat and mouse. They tested each other, tracking the other side’s submarines and preparing for a full battle of the north Atlantic — which fortunately never materialized.

After the fall of the Berlin Wall, the U.S. drew down the overall size of the Atlantic Fleet, correctly believing that the Russian Federation did not pose the kind of threat represented by the old Soviet Union. Fast forward to the rule of Vladimir Putin, who has rebuilt the Russian fleet — especially its undersea forces. In his recent “weapons video,” he showed many new weapons that could be launched from the Atlantic against the American mainland and sea defenses, including hypersonic cruise missiles and nuclear-powered undersea torpedoes.

2nd, the return of 2nd Fleet helps re-energize NATO as a maritime force in the Atlantic. While I was supreme allied commander at NATO, the former NATO Atlantic Command, or Saclant, had atrophied into a test bed for innovation and training and was a shadow of its former self. Alongside the return of 2nd Fleet, NATO has announced a new Atlantic Command as well, which will be embedded within the larger 2nd Fleet.

Both will be based in Norfolk, Virginia, and the efficiencies of combining them will allow far better allied participation in U.S. military efforts in the Atlantic Ocean. Look for British, French, German, Italian, Spanish and other advanced warships from Europe to be calling in U.S. ports and operating extensively with our forces from the Arctic down to the Caribbean and well into the deep Atlantic. Both commands will be headed up by a single three-star vice admiral, with staff officers from across the 29 nations of the NATO alliance.

Third, the new 2nd Fleet/NATO command will be responsible for specific operations to thwart Russian attempts to dominate the northern portions of the Atlantic.

All of this means more tension closer to U.S. shores. Alongside the dangerous military operations in Syria, where U.S. and Russian forces are literally within rifle shot of each other, the waters of the North Atlantic will become a zone of serious potential conflict.

At the broadest strategic level, the U.S. and its allies need to continue to search for meaningful ways to reduce tensions with the Russian Federation across the range of disagreements they face. Otherwise, the chances of the 2nd Fleet going into combat will continue to rise.

James Stavridis is a retired Navy admiral and dean of the Fletcher School of Law and Diplomacy at Tufts University.