As the commander of North American Aerospace Defense Command and U.S. Northern Command — two distinct commands with complementary missions and capabilities — my top priority is the defense of the United States and Canada. In recent years, the front line of homeland defense has shifted north. The Arctic is a potential approach for our adversaries to conduct strikes on North America and is now the front line in our defense.

The defense of our nations depends on our ability to detect and defeat attacks on Canada and the United States wherever they arise. Achieving the capabilities necessary for military operations in the Arctic requires deliberate engagement and coordination with key stakeholders, and we are rolling up our sleeves and driving solutions to meet the inherent challenges of Arctic operations.

Prudent investments in surveillance, communications, infrastructure and presence are necessary for developing and maintaining a credible military capability in the Arctic. In some cases, like the U.S. Navy’s Mobile User Objective System satellite communication system or the U.S. Air Force’s air operations, we are working with the services to apply current capabilities to enhance future operations. In others, like NORAD’s North Warning System, we are driving advance procurement for radars and space-based systems.

On any given day, NORAD’s binational forces are undertaking continuous aerospace and maritime warning and aerospace control in the defense of North America, including our shared northern approaches. Similarly, USNORTHCOM forces are always on watch in the Arctic, directing operations, maintaining a presence in Alaska’s harsh wilderness and surveilling some of the world’s most foreboding coastlines. We are actively transforming how we operate, exercise and think about the defense of our nations. Along with allies and partners, we are assessing changing environmental and strategic conditions throughout the region — across borders and operational boundaries — in an ongoing, active and collaborative effort to support safe, responsible use of the Arctic and, where necessary, reduce the risks associated with increased civilian and military presence.

We are again in a period of great power competition where our peer competitors are developing the strategies and advanced weapon systems they believe are needed to undermine American global leadership. Adversaries seek to diminish the position of strength on which our diplomats depend by putting at risk our ability to project power. Their strategies, advanced weapon systems and public statements indicating their intent to use them erode the sanctuary our geography once afforded.

Though other combatant commanders’ areas of responsibility meet in the Arctic, the commander of USNORTHCOM is uniquely responsible as the Department of Defense’s advocate for Arctic capabilities. USNORTHCOM is reinvigorating our role with the services to resource military capability needed for effective homeland defense. U.S. Air Force investments in the Arctic include training and equipping for cold-weather operations, operating fifth-generation aircraft out of northern bases and sustaining valuable training assets like the Joint Pacific Alaska Range Complex.

The U.S. Navy is focusing on future development and Arctic operations. The lessons learned from the aircraft carrier Harry S. Truman’s recent deployment above the Arctic Circle as part of a NATO exercise — the first Arctic deployment in nearly three decades by a U.S. aircraft carrier — will inform USNORTHCOM’s Arctic operations and advocacy efforts.

Above all, achieving the capabilities necessary for military operations in the Arctic requires deliberate engagement and coordination. I appreciate congressional leadership and support as we work together to advance military capabilities. Last September, I was grateful for the opportunity to brief Senate Armed Services Committee Chairman Jim Inhofe and ranking member Sen. Jack Reed, as well as Alaska Sen.‎ Dan Sullivan, on our DoD advocacy for progress on Arctic capabilities and the planned way ahead. As we approach posture hearings, I look forward to our continued close collaboration.

Our adversaries are rapidly acquiring the capability and capacity to hold our citizens, our way of life and our national interests at risk. Along with our partners and allies, we must adapt to the evolving strategic landscape and associated challenges to ensure we are ready to operate in and through the Arctic in all scenarios, across all domains, and against any adversary. Our homelands are not a sanctuary, and the Arctic is the front line in our defense.

Gen. Terrence O’Shaughnessy is the commander of North American Aerospace Defense Command and U.S. Northern Command at Peterson Air Force Base in Colorado Springs, Colorado. His commands’ top priority is homeland defense.