The Pentagon says it's not worried about a couple of Russian Akula-class attack submarines patrolling some 200 miles off the US Eastern coast -- that it raises no "red" flags at the moment.

Fair enough -- but the boats should still prompt long-term concern.

Sure, the Russkies are free to exercise their rights in international waters that lie beyond the traditional 12 miles of territorial seas off our coasts.

And the Akula ("shark") is an attack sub -- not the ballistic-missile subs that carried city-busting, nuclear-tipped ICBMs off our coasts in the Cold War.

The nuclear-powered Akulas are designed to sink enemy ships and subs with torpedoes or super-fast cruise missiles. They may even be able to undertake some limited land attack missions as well.

But generally, these Russian boats aren't particularly sexy. They're vintage 1980s -- Maybe Moscow was hoping for a submarine version of "Cash for Clunkers"?

They're also a bit noisy. It doesn't seem to have been a problem for US forces to track them as they transited the North Atlantic to the waters off the southeastern United States.

So far, so good. But let's dig a little deeper.

First, there's international politics. The Russians are trying to exert themselves as a great power on the world stage. A little military muscle-flexing rarely fails to make an impression -- and we're a prime target.

Indeed, the "sharks" off our beaches mark the first Russian sub deployment to our neighborhood since just about the end of the Cold War.

Despite the White House efforts to paint the July presidential summit in Moscow as a success and a "reset" in relations, the Kremlin is clearly still unsettled by US policies.

There's also domestic politics. Russian subs lurking off a Cold War enemy's coast (and pix of a bare-chested Prime Minister Vladimir Putin) are great for stoking nationalist flames, especially when times are tough around the dacha -- which means we may see more of this.

And there's navy politics. Russia's fleet has been dashed upon the rocks a bit lately. A new sub-launched ballistic missile, named Bulava, has suffered a number of failed launches, causing a slew of sackings.

This program is sensitive in Moscow: The Bulava was to be capable of defeating missile-defense systems, a top Russian paranoia at the moment.

In fact, the fleet's missile program has been such a disaster that some Russian commentators are warning of the utter collapse of their once-mighty navy, which traces its roots back to Peter the Great.

So, in deploying subs off a US coast, the Russian brass in blue may have been looking for some job security through a little self-serving saber-rattling.

Then there's one more bit of longer-term context: The Akulas can now be added to a growing list of Russian military appearances nearby, including strategic bomber patrols in the Atlantic, Pacific and Arctic and ship visits to Latin America.

The trend isn't positive -- and could get worse.

Indeed, some believe Moscow wanted the subs to be detected, so as to send a signal to Washington of what may lie in store if the White House doesn't come around more to the Kremlin's way of thinking.

Which raises the question: What's Russia's next move along these lines?

That's something the Pentagon and its superiors should be worrying about now.

Peter Brookes is senior fellow for National Security Affairs in the Davis Institute at The Heritage Foundation.