The dark clouds gathering this summer between Moscow and the West have some experts concerned that the world is on the brink of a new cold war. They point to two flash points. One, the ex-Soviet state of Georgia, is largely driven by Moscow's fear of NATO expanding into its traditional sphere of influence. The other is a proposed US missile-defense shield in Eastern Europe. Russia has promised to retaliate – possibly by basing nuclear-capable bombers in Cuba, according to an unofficial news report quoting unnamed top security officials last week.

"It's no longer just rhetoric, it could start to get quite serious," says Dmitri Trenin, an analyst with the Carnegie Center in Moscow. "The message being put out by Moscow is that the West needs to realize that it's approaching a line, beyond which there could be a real showdown."

But Russian President Dmitri Medvedev, has a plan to arrest the slide by creating an alternative to NATO. Though it has yet to gain traction in the West, Mr. Medvedev's plan, announced in Berlin last month, has been much discussed in the Russian media. In short, it would redesign Europe's security system from the bottom up – but this time, Russian would participate as an equal partner and founder of the new bloc. Russian experts are dubbing the concept "EATO" – Euro-Atlantic Treaty Organization – a big-tent security grouping that would replace NATO – the North Atlantic Treaty Organization – and say it is likely to become the signature foreign policy theme of Medvedev's presidency. It would also, say supporters, remove the main irritant in Russia's relations with the West today.

Unlike the former cold war, Russian officials argue, today's growing rift between Moscow and the West is not based on irreconcilable ideological or geopolitical hostility. The main problem, they say, stems from the West's failure to work with Russia to re-imagine global security architecture following the USSR's collapse. Confidantes of former Soviet President Mikhail Gorbachev say that US leaders reneged on pledges to build a "new world order" after Soviet troops withdrew from Eastern Europe and the Communist military alliance – the Warsaw Pact – was disbanded.

"Gorbachev made deep concessions to the West in order to break out of the vicious cycle of the arms race. But later, when Russia was going through a painful economic transition and we needed support, the West turned away," says Andrei Grachev, who was a Kremlin adviser and Gorbachev's presidential spokesman at the time. "Despite promises that had been given to us, the West decided to use [Russia's weakness and economic turmoil] in order to expand NATO to the east. I believe that the anti-Western moods present in Russian society today can be explained by the fact that the West treated Russia as a vanquished enemy," rather than a potential partner, he says.

The sorest point is the inexorable advance of NATO into the USSR's former sphere which could soon see inclusion of the ex-Soviet states of Georgia and Ukraine. Little has come from past attempts to develop a NATO-Russian partnership, and Moscow views the Western alliance as a cold war artifact that unites European countries against Russia. "Russia's view is that NATO creates new divisions in Europe," says Tatiana Parkhalina, director of the official Center for European Security Studies in Moscow. Unlike the previous cycle of NATO expansion, which took in Eastern European states of lesser strategic concern to Russia, the new candidates are part of the core of the former USSR. "Ukraine is felt by Russians as part of traditional Russian lands. To many Russians it's just unthinkable for it to become part of an outside military alliance," she says.

Mr. Trenin argues that if Ukraine is admitted to NATO's membership action program, which could happen as early as December, "that would start a political warfare campaign in Ukraine," he says. "I see Russia ceasing to value the sovereignty of Ukraine now that it's dropping into the US lap. I see a harshening of the tone in Moscow. The whole foreign policy of Russia will change."

Another looming flashpoint is US determination to install antimissile installations in Eastern Europe to counter what it sees as a nuclear missile threat from rogue states such as Iran and North Korea. At the Group of Eight summit in Japan earlier this month, Medvedev promised to "retaliate" if the scheme to build radars in the Czech Republic and deploy interceptor rockets in Poland is finalized.

In what experts say were a series of calculated leaks to Moscow newspapers last week, the Kremlin let the world know what such retaliation might look like. It could come in the shape of medium-range nuclear missiles based in the Russian Baltic enclave of Kaliningrad and targeted on European capitals. Or, according to a detailed report in the daily Izvestia that cited top military sources, Russia might revive an old Soviet-era airfield in Cuba as a base for its Tu-95 and Tu-160 long-range nuclear bombers. Russian officials denied the stories, but experts say there's little doubt they were Kremlin-approved.

"I don't think Russian bombers in Cuba is something to be seriously discussed at the moment, but the leak was clearly designed for psychological impact," says Fyodor Lukyanov, editor of Russia in Global Affairs, a leading foreign-policy journal. "These stories say to the West: 'You'd better start thinking about this, because we are very, very serious.' "

The Russian alternative, outlined by Medvedev in various statements, is a vague project that would be kicked off by a pan-European meeting of government leaders and security experts to develop a new concept that would include all the post-Soviet states, including Russia. One of the main aims of his presidency, he said, will be to establish a strategic partnership with the European Union that could be the mainstay of a "big Europe without dividing lines."

"The issue of rejoining Europe will be the central theme for Medvedev, whether his proposal is accepted or not," says Gleb Pavlovsky, a longtime Kremlin adviser. "The existing architecture is in crisis, and it isn't working. We need a new design, with an emphasis on security for all countries in Europe."