There's a new round of tensions between the US, NATO, and Russia, and that means there's a new battle brewing in the Atlantic

• The North Atlantic was a central battleground during the world wars and the Cold War, serving as the strategic link between the US and Europe.
• With the opening of a new period of competition between the US and its NATO allies and a resurgent Russia, the North Atlantic is once again vitally important.
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The National Defense Strategy issued by the Defense Department in 2018 declared a new era of great power competition with "revisionist powers" - namely, China and Russia.

A new period of tension and competition with Russia has been evident in Europe since 2014, when Moscow seized Crimea from Ukraine.

In the years since, NATO has sought to improve its position in Europe, while Russia has displayed new naval capabilities in the waters around the continent.

In an email interview, Magnus Nordenman, a NATO expert and author of "The New Battle for the Atlantic: Emerging Competition with Russia in the Far North" who was previously director of the Transatlantic Security Initiative at the Atlantic Council, explained what this new era of competition in the Atlantic looks like, what each side brings to it, and how the conditions continue to change.