Putin's Russia in biggest Arctic military push since Soviet fall

* Russia is fortifying Arctic, pouring in money and missiles

* New generation of nuclear icebreakers is being built

* New bases are rising, derelict airfields being unsealed

* Arctic rivals look on amid fears of new arms race

* Moscow is eyeing new territory, mineral wealth, sea route

By Andrew Osborn

MURMANSK, Russia, Jan 30 (Reuters) - The nuclear icebreaker Lenin, the pride and joy of the Soviet Union's Arctic great game, lies at perpetual anchor in the frigid water here. A relic of the Cold War, it is now a museum.

But nearly three decades after the Lenin was taken out of service to be turned into a visitor attraction, Russia is again on the march in the Arctic and building new nuclear icebreakers.

It is part of a push to firm Moscow's hand in the High North as it vies for dominance with traditional rivals Canada, the United States, and Norway as well as newcomer China.

Interviews with officials and military analysts and reviews of government documents show Russia's build-up is the biggest since the 1991 Soviet fall and will, in some areas, give Moscow more military capabilities than the Soviet Union once had.

The expansion has far-reaching financial and geopolitical ramifications. The Arctic is estimated to hold more hydrocarbon reserves than Saudi Arabia and Moscow is putting down a serious military marker.

"History is repeating itself," Vladimir Blinov, a guide on board the icebreaker Lenin, which is named after communist revolutionary Vladimir Lenin, told a recent tour group.

"Back then (in the 1950s) it was the height of the Cold War and the United States was leading in some areas. But we beat the Americans and built the world's first nuclear ship (the Lenin). The situation today is similar."

Under President Vladimir Putin, Moscow is rushing to re-open abandoned Soviet military, air and radar bases on remote Arctic islands and to build new ones, as it pushes ahead with a claim to almost half a million square miles of the Arctic.

It regularly releases pictures of its troops training in white fatigues, wielding assault rifles as they zip along on sleighs pulled by reindeer.

The Arctic, the U.S. Geological Survey estimates, holds oil and gas reserves equivalent to 412 billion barrels of oil, about 22 percent of the world's undiscovered oil and gas.

Low oil prices and Western sanctions imposed over Moscow's actions in Ukraine mean new offshore Arctic projects have for now been mothballed, but the Kremlin is playing a longer game.

It is building three nuclear icebreakers, including the world's largest, to bolster its fleet of around 40 breakers, six of which are nuclear. No other country has a nuclear breaker fleet, used to clear channels for military and civilian ships.