The Russians are at it again. After penetrating British airspace last March with two Tupolev 160 bomber planes, a specially upgraded Akula class submarine was caught trying to record the acoustic signature made by the Vanguard submarines that carry Trident nuclear missiles.

The Telegraph reports that British submariners are experiencing the highest number of “contacts” with Russian submarines since 1987.

If the Russians are able to obtain a recording of the unique noise of the boat’s propellers it would have serious implications for Britain’s nuclear deterrent. Using its sophisticated sonar, the Akula would be able to track Vanguards and potentially sink them before they could launch their missiles.

Royal Navy commanders are supposed to have ordered a Trafalgar class nuclear submarine to protect the Vanguard. Four Vanguard class boats are currently operational, each armed with up to sixteen Trident II submarine launched ballistic missiles that are capable of delivering a nuclear warhead. All are based at the Clyde naval base, on Scotland’s west coats, 25 miles from Glasgow.

Evidently, the British haven’t been the only ones subject to Russian harassment lately. “The Russians have been playing games with us, the Americans and French in the North Atlantic,” one senior Navy commander told the Telegraph.

It’s difficult to tell what the Russians are up to. Arctic tensions have been rising in recent months, with Moscow claiming more of its fair share of the North Pole. That may account for the newfound assertiveness on Russia’s part. Internal politics may also be to blame: particularly the first half of the Putin-Medvedev twosome can cling to power because of older Russians’ reminiscence of the good ol’ days that were Soviet Empire. Every now and then the Russian bear must roar to convince itself that it’s still relevant.

Or maybe Newsweek‘s Owen Matthews was right after all when in March of this year, he accused the Russians of “playing the nuisance card. To remain important,” he believes, “Russia has to be seen as an obstacle.” They certainly are.