Washington (CNN) Russia currently poses the greatest global threat to the United States, according to the man slated to be President Barack Obama's top military adviser.

"Russia presents the greatest threat to our national security," Gen. Joseph Dunford told the Senate Armed Services committee during his confirmation hearing to be the next Chairman of the Joint Chiefs of Staff.

With its large nuclear arsenal, destabilizing role in Ukraine and threat to NATO nations on its borders, Russia presents a significant challenge to the U.S., even as it faces threats like that of ISIS.

"If you want to talk about a nation that could pose an existential threat to the United States, I would have to point to Russia," Dunford said. "And if you look at their behavior, it's nothing short of alarming,"

Photos: Russian warplane intercepts Photos: Russian warplane intercepts A Russian Tu-95 Bear bomber is escorted by a British Royal Air Force Typhoon fighter during an intercept in September 2014. Click through the gallery to see other intercepts in late 2014. Hide Caption 1 of 12 Photos: Russian warplane intercepts NATO Secretary General Jens Stoltenberg said in November that alliance fighters had intercepted Russian warplanes as they flew close to NATO countries more than 400 times in 2014, the kind of Russian air activity not seen since the Cold War. Hide Caption 2 of 12 Photos: Russian warplane intercepts An armed MiG-31 intercepted by Norwegian planes. The plane is nicknamed the Foxhound by NATO. Hide Caption 3 of 12 Photos: Russian warplane intercepts An armed Tu-22M supersonic bomber, nicknamed the Backfire by NATO, was photographed by Norwegian fighter jets. Hide Caption 4 of 12 Photos: Russian warplane intercepts A look at a Russian Tu-22M from below as taken by a Norwegian Royal Air Force fighter plane. Hide Caption 5 of 12 Photos: Russian warplane intercepts A Su-24 attack aircraft, nicknamed the Fencer by NATO, was photographed by a Norwegian warplane. Hide Caption 6 of 12 Photos: Russian warplane intercepts An armed MiG-31 Foxhound photographed from below by a Norwegian Royal Air Force interceptor. Hide Caption 7 of 12 Photos: Russian warplane intercepts A Russian Il-78 tanker refuels a Tu-95 Bear bomber in a photograph taken by a Norwegian warplane. Hide Caption 8 of 12 Photos: Russian warplane intercepts Two Russian Sukhoi Su-34 fighter bombers, nicknamed the Fullback by NATO, as photographed by Finnish Air Force F/A-18 Hornet fighters. Hide Caption 9 of 12 Photos: Russian warplane intercepts Finnish fighter jets photographed this Russian Tu-95 Bear bomber. Hide Caption 10 of 12 Photos: Russian warplane intercepts Two Tupolev Tu-22M aircraft intercepted by Finnish fighter planes. Hide Caption 11 of 12 Photos: Russian warplane intercepts A Russian Tupolev Tu-95 Bear bomber intercepted by Finnish fighter planes. Hide Caption 12 of 12

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