James Holmes is a professor at the Naval War College , co-author of " Red Star Over the Pacific ," and a US Navy surface-warfare officer of Cold War vintage. The views expressed in this commentary are his own.

Ho, hum.

Viktor Leonov first appeared off Delaware and, at this writing, is loitering south of the US submarine base at Groton, Connecticut. The ship is undoubtedly vacuuming up electronic signals emanating from the base, monitoring the US Navy's comings and goings and gleaning anything it can about the construction of new US submarines.

Beyond the immediate benefits of gathering intelligence, President Vladimir Putin's government is sending a specific message by dispatching Viktor Leonov to the western Atlantic Ocean. Just as the US Navy commonly deploys warships to seas that wash against Russian shores, in particular the Black Sea and Baltic Sea , the Russian Navy can reciprocate by mounting a presence of its own in US home waters.

In other words, two can play America's game.

It's worth remembering what a common maritime game this was during the Cold War. Ever since the US Navy sank the Imperial Japanese Navy in World War II, it has seen itself as the guardian of freedom of the seas and as the sharp edge of US foreign policy. At the height of the Cold War, US mariners mounted a standing presence in potentially embattled waters. Ships voyaged around the Eurasian periphery constantly, close to the Eastern Bloc shores.

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Rather than submit meekly to American dominance of the world's oceans and seas, the Soviet Union built an oceangoing fleet larger, albeit more technologically backward, than the US Navy fleet. By the 1970s, in fact, the Soviet Navy was active not just in the vicinity of Soviet coastlines but throughout the Seven Seas. This included American-dominated "lakes" like the Mediterranean Sea. During the 1973 Arab-Israeli war, for instance, the Soviet contingent in the Eastern Mediterranean outnumbered the Italy-based US Sixth Fleet -- and shocked US commanders in the process.

But such interactions became routine during the end of the Cold War. Each navy shadowed the other's ships and aircraft. Fleet commanders departing from, say, Pearl Harbor, knew a Soviet "AGI" -- a fishing trawler packed with electronic snooping gear, and a forerunner to Viktor Leonov -- would be lurking offshore and would follow along to collect signals intelligence and information about American tactics and practices. Prudent US commanders took to assigning the AGI a station in the formation, lest it get in the way or cause a collision when the task force changed course or speed.

Soviet ships became de facto members of US fleets!

That's not to say high-seas interactions were always so cordial. Sometimes they were downright harrowing. US and Soviet submariners played cat-and-mouse games with one another, and with adversary surface vessels, throughout the Cold War. Sometimes the two navies nearly came to blows, as during the " Black Sea bumping incident " of 1988, when two Soviet frigates deliberately collided with an American cruiser and destroyer skirting close to the Crimean Peninsula.

Mostly, though, Washington and Moscow managed their maritime interactions in the interest of preventing war. They concluded an Incidents at Sea Agreement designed to forestall escalation when US and Soviet ships encountered each other at sea. In short, each navy sought to deter the other while grudgingly tolerating its presence in nearby seas.

For Americans, this is the price of a globe-spanning maritime strategy. US maritime strategy envisions stationing forces in proximity to potentially hostile shorelines. As a matter of reciprocity, Washington can hardly refuse Russian -- or Chinese, or Iranian -- fighting ships the right to approach American coasts, provided they comply with the rules set forth by the law of the sea . They may pass within 12 nautical miles of our shorelines while conducting " innocent passage ."

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And Viktor Leonov appears to be in compliance with this law.

The habit of tolerating rival navies' presence is a habit worth relearning. The post-Cold War age, the age when the US Navy was the undisputed master of the sea, is drawing swiftly to a close. Russia's navy is returning to the sea after a quarter-century when its ships sat rusting at their moorings. China has built a navy that's set to outnumber the US Navy within the foreseeable future.

Competition against rival navies is once again a fact. Americans and their elected officials had better get used to it.