EIELSON AIR FORCE BASE, ALASKA - Alaska is the northernmost part of the United States, and it is big. Big in land mass, and big in military power.

There's a lot of wild, open space between military installations in Alaska. Grizzly bears prowl nearby, and the weather is wild, too. In the winters it can get down to around minus 45 degrees Celsius.

So why would the U.S. place so many of its troops and defenses in such a harsh environment? The answer, according to Defense Secretary Lloyd Austin, is geography.

"We are an Indo-Pacific nation, and we are an Arctic nation. And here in Alaska, those two critical regions intersect," he said.

Alaska is bordered by the Pacific Ocean and the Arctic Ocean. Eielson Air Force Base, in the heart of Alaska, is about 160 kilometers from the Arctic circle. There, Austin said, the U.S. has beefed up defenses and expanded training in an effort to increase its competitive edge over near-peer adversaries Russia and China.

"You've seen us increase our capability up here recently with the arrival of additional F-35s, and we're in the process of building out capabilities to support that effort," he said.

Which is especially useful since fifth-generation F-35 fighter jets based at Eielson can reach anywhere in the northern hemisphere. Fly over the north Pacific? You're in Asia. Want to get to Europe? Just hop across the Arctic.

Need to practice military skills at home? There's a 200,000-square-kilometer training range here.

"Unless you've served here people don't fully understand how strategically important our state is," said Alaskan Senator Dan Sullivan who a member of the Senate Armed Services Committee.

He said the Pentagon is right to focus on high-end competitors, but he's worried the U.S. may not be keeping up.

"China has been increasing its defense spending by 10% a year, right? They're going to keep doing it. We, you know, second term of the Obama administration, cut defense spending by 25%. Trump got back on it. It's going down again. So, absolutely I'm concerned, and so are most members of the Armed Services Committee, doesn't matter what party," he said.

Sullivan said he wants to see a defense budget that grows 3 to 5% annually to keep pace with Chinese military investments. And he points to the bases spread across America's last frontier state as a testament to how defense dollars can go a long way, a long way from Washington.