( CNN ) -- Last week , the news broke that Russian aircraft will commence patrolling the skies over the Caribbean Sea and Gulf of Mexico . Washington reacted mildly to Defense Minister Sergey Shoigu 's announcement . The U.S. State Department questioned Moscow 's rationale for operating off North American coastlines while insisting that such flights `` must be consistent with international law and conducted with due regard for the rights of other nations and the safety of other aircraft and of vessels . '' That 's about it . Nor should Washington go further than this pro forma statement . Why ? Because an informal compact preserves freedom of the seas and skies . Coastal states grit their teeth and tolerate rivals ' presence in exchange for their own freedom to operate along foreign shores . It 's a form of reciprocity . Shoigu 's announcement came the same week a Russian naval flotilla appeared off Australia 's northern periphery , setting commentators abuzz Down Under . But Prime Minister Tony Abbott 's government , like the Obama administration , struck the right , low-key note vis-Ã -vis that voyage . Defense spokesmen noted that the Russian vessels -- guided-missile cruiser Varyag , along with a three-ship retinue -- were doing nothing unlawful or especially provocative . And indeed they were n't . No one claimed the Russian task force passed through Australian territorial waters , the 12-nautical-mile belt of sea off any coastal state 's shores . ( Although it could have done so , provided commanders complied with the rules of `` innocent passage . '' ) No one claimed it placed Australian security at risk . As coastal states will , nevertheless , Canberra dispatched assets to keep watch . Royal Australian Navy men-of-war and surveillance aircraft took to sea and sky to monitor the Russian warships ' whereabouts and , presumably , document their activities . And so things stand . Move , countermove : That 's a normal day in the life of sea services . Why would Moscow go to the trouble of mounting a Pacific cruise so far from Russian shorelines ? Thucydides , the chronicler of the Peloponnesian War , offers a starting point for answering such questions . He lists `` fear , honor and interest '' as three of the prime movers for human actions . Each is probably shaping decisions in Moscow . Take Thucydides ' motives in reverse order . The Russian leadership probably saw an interest in telegraphing how seriously it takes the G20 summit that has been taking place in Brisbane . It may also want to impress prospective Southeast Asian buyers of Russian weaponry . Displaying naval prowess in Australia 's extended neighborhood , then , could constitute part of a sales pitch . Artfully employed , ships remain tokens of political and economic interest , today as throughout maritime history . And honor ? Russia clearly wants to announce , yet again , its return to history . A painful interlude of weakness followed the Soviet Union 's downfall . Sending a rejuvenated Pacific Fleet to promenade around the region helps banish bad memories while restoring luster to Russia 's reputation as a great power . On the personal level , moreover , the cruise could represent President Vladimir Putin 's way of replying to Abbott 's vow to `` shirtfront , '' or upbraid , Putin over last summer 's downing of a Malaysian airliner over Ukraine . Childish ? Maybe . But hardly unprecedented . Political leaders have been known to use implements of state to avenge personal slights . Lastly , fear . Moscow doubtless feels beleaguered . The international community reacted vehemently to Russia 's proxy war against Ukraine , levying an array of sanctions . Russia 's isolation is a problem of its own making , to be sure . But staging naval forces in the South Pacific reminds the West and its allies that Moscow still has options . In all likelihood , then , a variety of motives are at work . And yet forbearance remains the best posture , regardless of what is behind Russian actions . Why ? To uphold the principle of freedom of the seas . Australian warships and warplanes traverse the global commons -- the seas and skies beyond any coastal state 's jurisdiction , open to unfettered use by all -- every day . The same goes for American ships and planes , those from Japan and South Korea , and on and on . Indeed , it 's virtually impossible to project power into faraway regions or carry on marine commerce unless the commons remains open . Such untrammeled liberty is an asset beyond price . Accordingly , it behooves great sea powers such as Australia and the United States -- the biggest beneficiaries of freedom of the sea -- to make every effort to keep the commons a commons . That means refraining from words or acts that corrode the freedom embedded in international law and practice . Overreacting to routine use of the commons because we dislike the power using it sets a double standard : freedom for me , but not for thee . That 's the worst way to respond . Better to watch , wait and keep mum until and unless a foreign navy does something unlawful . In a sense the seafaring world is renewing a very old argument about the law of the sea . Romans saw an ever-increasing swath of the Mediterranean Sea as `` mare nostrum , '' or `` our sea . '' In this view the sea was subject to ownership . Dutchman Hugo Grotius , one of the forefathers of international law , countered during the 17th century with the idea of the free sea , or `` mare liberum . '' Beyond the range of a cannon shot from shore -- the farthest offshore a government could exert control -- mariners were at liberty to pursue trade and commerce , project naval force , and undertake any number of seaborne ventures . Grotius ' foil -- ironically , since it was Great Britain that later midwifed the liberal maritime order we know today -- was the English jurist John Selden . Selden put forth the countervailing doctrine of `` mare clausum , '' the closed sea . The gist of mare clausum was that governments were entitled to exercise sovereign jurisdiction over sea space , much as they did on dry land . Coastal states could literally rule the waves -- just as they wielded a monopoly of legitimate force within their terrestrial frontiers . Selden insisted that England was sovereign over northwestern European waters -- including the approaches from the Atlantic Ocean high seas to Dutch seaports . Small wonder Grotius wanted to deny rival England the right to dictate the terms of his homeland 's access to the sea lanes -- or cut that vital lifeline altogether . A similar quarrel played out in South Asia , where Portugal styled itself the lord of the Indian Ocean while the Dutch clamored for free access . Hugo Grotius ' doctrine of free seas ultimately seemed to win out . Grotius remains a fixture in international-law circles , while John Selden is a largely forgotten figure . But there are few permanent victories in legal debates . Protesting deployments like Russia 's too loudly gives Selden 's intellectual descendants comfort -- to the detriment of freedom of the seas . China , for instance , claims the right to make the rules governing merchant and naval traffic crisscrossing the South China Sea . It wants to forbid military surveillance , underwater surveys , and other endeavors explicitly permitted by the law of the sea . It wants to amend the system by fiat . Australia could unwittingly advance China 's project . If Canberra objected vehemently to plainly lawful maritime endeavors , that is , it would have implied that Beijing has a point when it constricts freedom of the seas and skies for fellow seafaring states . That point being that the nearby coastal state can regulate who operates in the commons , who does n't , and on what terms . By soft-pedaling the Russian deployment , on the other hand , Australia denies proponents of the closed sea that aid and comfort . And this is a deployment worth soft-pedaling in any event . The Australian press duly pointed out that one of the four Russian vessels was an oceangoing tugboat , sent along in case one of the combatant ships suffers a mechanical breakdown or some other cataclysm . Dispatching a tug as a matter of routine betokens a navy less than confident in its hardware , material upkeep and basic seamanship . U.S. Navy expeditionary forces do n't travel with tugboats . We do n't expect to break down at sea . The same goes for the Royal Australian Navy and the other highly professional services fielded by America 's allies . Target audiences notice such things -- and they detract from the political impact of a naval deployment . One doubts this month 's voyage will reap much benefit for Moscow . So let 's make softly , softly the principle guiding diplomacy toward naval voyages -- those undertaken by prospective foes as well as by allies and friends .
James Holmes : Mild reaction correct over Russia 's Caribbean plan . Comment: Moscow doubtless feels beleaguered , he says .