BARROW, Alaska — In past years, these remote gray waters of the Alaskan Arctic saw little more than the occasional cargo barge and Eskimo whaling boat. No more.

This summer, when the U.S. Coast Guard cutter Bertholf was monitoring shipping traffic along the desolate tundra coast, its radar displays were often brightly lighted with mysterious targets.

There were oil drilling rigs, research vessels, fuel barges, small cruise ships. A few were sailboats that had ventured through the Northwest Passage above Canada. On a single day in August, 95 ships were detected between Prudhoe Bay and Wainwright off America’s least defended coastline, and for some of them, Coast Guard officials had no idea what the vessels were carrying or who was on them.

“There’s probably 1,500 people out there,” Rear Adm. Thomas Ostebo, commander of the Coast Guard’s 17th District in Alaska, said at a recent conference of Arctic policymakers near Anchorage. “It’s kind of spinning a little bit out of control.”

The rapid melting of the polar ice cap is turning the once ice-clogged waters off northern Alaska into a navigable ocean, and the rush to grab the region’s abundant oil and mineral resources by way of new shipping lanes is posing safety and security concerns for Coast Guard patrols.

What happens if a cruise ship gets stranded in stray ice? Or if a sailing vessel capsizes off an uninhabited coast?

“Yesterday, we saw three sailing vessels in 24 hours,” said the Bertholf’s commander, Capt. Thomas E. Crabbs.

The Coast Guard this summer ran Arctic Shield, the most extensive patrol operation it has ever mounted in the Arctic. It set up a temporary operating base and remote communications station at Barrow.

A fleet of cutters, buoy tenders, helicopters and boarding vessels deployed across the Beaufort, Chukchi and Bering seas to oversee new offshore oil drilling operations offers search-and-rescue if needed and provides notice to burgeoning ship traffic that the U.S. is monitoring its northernmost border.

The rush for riches as Russia, Norway and Canada vie with the U.S. for the Arctic’s mineral resources, and the possibility that drug dealers, arms merchants and terrorists could begin to explore transport routes near America’s largest oil fields have prompted the U.S. military to begin planning for a future in the Arctic much more substantial than it had envisioned.

The U.S. Naval War College last year conducted war games simulating the sinking of a ship carrying weapons of mass destruction from North Africa to Asia across the top of Canada and Alaska.

The Air Force has been practicing how to make food and survival gear drops to survivors of a large plane crash in the unbelievably remote Brooks Range, north of Fairbanks.

The North American Aerospace Defense Command, known as NORAD, already has gone beyond drills: F-15 fighters have been launched on interceptions at least 50 times during the last five years in response to Russian long-range bombers – not previously seen here since the Cold War – which have been provocatively skirting the edges of U.S. airspace.

Through it all, U.S. security forces are battling historically sketchy radio communications, vicious storms, shifting ice floes and huge distances from base: Coast Guard cutters must sail 1,200 miles south just to take on food and refuel.

“All of the uniqueness of operating up in the Arctic represents huge challenges for us,” said Royal Canadian Air Force Col. Dan Constable, deputy commander of NORAD’s Alaska region.

The Naval War College games in September 2011 were an early test, and not an encouraging one. Many of the scenarios rehearsed, former Navy Cmdr. Christopher Gray said, ran into problems with poor communications and trouble maintaining supplies of food, fuel and supplies.

“Does the Navy have the ability to go up and operate a number of ships, a number of aircraft, for a sustained period of time in this environment, where it’s cold, it’s got bad weather, it’s got a lot of ice, and it’s really far away from everything that supports you? What we found is that the answer is, not really,” Gray said.

The Bertholf is especially suited to summertime operations in the Far North. Though not capable of operating in ice, it is equipped with high-efficiency engines and stability systems that allow the vessel and its crew of 146 to remain in the Arctic for a month at a time – heretofore unheard of in the U.S. fleet.

“Because we’re present here and because we have the endurance to remain here throughout the season, we’re going to be able to understand who is in the maritime domain,” Crabbs said as a small vessel carrying boarding troops was launched off the Bertholf’s stern for a closer look at nearby shipping traffic.

U.S. officials say they are still several decades away from needing a full-scale military presence in the region, and with luck, there will be no need to resort to arms: The real source of conflict is the battle everyone faces – with the elements.

“If somebody were to invade the Canadian High North,” Canadian Forces chief of staff Gen. Walter Natynczyk said at the Arctic Imperative Summit, “my first problem would be to rescue them.”

The move to secure the Arctic goes well beyond domestic security. With easier access to the more than 90 billion barrels of oil and trillions of cubic feet of natural gas in the Arctic, nations are rushing to gain international recognition of territorial claims, mineral contracts and shipping routes.

On Aug. 2, the Chinese icebreaker Snow Dragon completed an unprecedented voyage across the top of the world through the Northwest Passage.

Icelandic President Olafur Ragnar Grimsson was paid a visit by a delegation of senior Chinese officials who wanted to discuss Beijing’s bid for permanent observer status in the Arctic Council, the suddenly powerful organization of eight nations with territory in the Arctic Circle.

“And China is not the only Asian country interested in the Arctic,” Grimsson said at the Arctic summit. Singapore and South Korea, he said, also want in.

The U.S. has been slow to stake out its own territory. While Russia has submitted a claim for thousands of miles of seabed, and Canada is asserting title to mineral-rich areas along the U.S. border, the United States is the only Arctic nation that has not ratified the 1982 treaty known as the United Nations Convention on the Law of the Sea – the international mechanism for brokering such claims.

The U.S. has also fallen behind on what the Coast Guard needs to patrol the new mineral development zones. The only working icebreaker is the cutter Healy, with a second being refurbished that is due to return soon. Russia, by contrast, has 25 icebreakers, according to the U.S. Congressional Research Service. Finland and Sweden have seven each, Canada six.

“I think it’s a real-time imperative for our nation to get its arms around these things,” Rear Adm. Ostebo said. “It’s critically important to understand that we do not control it. The rest of the world has a boat here, and we are late to the table.”