Both Moscow and Washington insist one Cold War was enough. But considering the chilly rhetorical winds blowing back and forth between the two capitals recently, it appears at least a passing cold front has descended on the relationship.

Today's Moscow is increasingly independent, prominent in global affairs, nationalistic at home, awash in energy wealth and bent on reasserting Russia as a great power with distinct interests.

Although the U.S. and Russia aren't necessarily destined to become steely eyed archenemies again like during the Cold War, they will continue to be rivals -- and clash on a whole host of issues of mutual concern.

In short, the bear is back.

At the center of the storm in U.S.-Russian relations is the feisty Russian president, Vladimir Putin. A decade and a half hasn't faded the former KGB colonel's nostalgia for the Soviet Union's glory days. In fact, in 2005, in a keen insight into Putin's thinking, he told the parliament in the president's annual address that the greatest geopolitical tragedy of the 20th century was the end of the Soviet Union.

Since taking office in 2000, Putin has set his sights on re-establishing Russia as a global force -- on par with the U.S., China and the European Union. To do this, Putin's Kremlin has reined in power at home and asserted itself abroad.

Internationally, Putin has been vigorously pushing back on what he sees as an encroachment on Russia's traditional sphere of influence in Eastern and Central Europe, the Baltic, the Caucasus and Central Asia -- what Moscow calls its "near abroad."

Putin is anxious about Ukraine's Orange, Georgia's Rose and Kyrgyzstan's Tulip democratic revolutions. NATO expansion and U.S. bases in Central Asia are painful reminders of just how far once-mighty Moscow has fallen since the Berlin Wall tumbled.

Putin's actions abroad are also directed at strengthening his already immense popularity at home, where pushing back on traditional rivals, especially the U.S., has broad appeal among both the elite and the commoners.

He's also exploiting a period of perceived American weakness and distraction to advance Russian interests across a number of fronts, while Washington seemingly can't respond as freely -- or as vigorously -- as it might otherwise.

Missile Defense Mania

The latest irritant in the U.S.-Russian relationship is American missile defense. Although the Kremlin agreed to end the 1972 U.S.-Soviet Anti-Ballistic Missile treaty in 2002, it seems to have changed its mind, at least to a certain degree.

Russia strongly objects to a U.S. proposal to put an X-band radar in the Czech Republic and deploy 10 interceptors in Poland to counter the growing Iranian threat, claiming it would cause an "arms race" and turn Europe into a "powder keg."

Moscow also complains that the proposed system undermines Russia's strategic nuclear deterrent. Although it doesn't, advanced U.S. missile defense likely would make the once-proud Russian military, especially the strategic forces, feel a tad bit emasculated. The Kremlin also insists it's unnecessary because Iranian missiles can't range central Europe yet. And Russian generals say the X-band radar is more about intelligence collection than fire control and could be used to spy on military movements deep into Russia.

As a result, Putin suggested to President Bush at this spring's G-8 summit in Germany that the U.S. and Russia share a leased Russian early-warning radar at Gabala, Azerbaijan, instead building the Czech radar. (Of course, a Soviet-era early-warning radar won't come close to matching the X-band radar's tracking capabilities, but the good news for the U.S. is the suggestion probably puts a nasty crimp in Russo-Iranian relations.)

Putin also suggested that the U.S. put its Eastern European missile defense interceptors in Iraq, Turkey or even at sea aboard Navy ships to defend against the Iranian missiles in their early phases of flight.

And in the latest twist in Russian thinking on missile defense, Putin made another counteroffer while with President Bush in Maine in early July: a regional missile defense with a radar facility in southern Russia under the NATO-Russia Council. The proposal caught the White House off guard -- and neither Bush nor Putin seemed willing to move off their positions for or against the planned Eastern European sites. The devil, as usual, is in the details.

Although the new offer may have promise, past attempts at cooperation on shared early warning and missile defense -- going back to presidents Boris Yeltsin and Bill Clinton -- have achieved little, if anything.

Treaty Trouble

In a putative response to Washington's Eastern European missile defense proposal, Moscow has threatened to vacate a number of arms control treaties, including the Intermediate-Range Nuclear Forces (INF) and Conventional Armed Forces in Europe (CFE) accords.

In February, senior Russian officials announced they were considering withdrawing from the 1987 INF treaty, which bans U.S. and Russian ballistic and cruise missiles with ranges of 500 to 5,500 kilometers, citing Eastern European missile defense as the cause. Indeed, Deputy Prime Minister Sergei Ivanov -- a possible successor to Putin in the 2008 presidential election -- called INF "a Cold War relic." But Putin probably wants out of INF because the agreement limits whole classes of missiles that Russia could deploy.

The Kremlin is understandably nervous about the spread of nuclear and ballistic missile capability among its neighbors lately, including China, Pakistan, India, North Korea and even Iran, while the Russians aren't able to field comparable systems. Russia also talked this spring of a moratorium on observance of the 1990 CFE accord, which limits forces in NATO and former Warsaw Pact countries. Although Moscow may be using CFE as a foil against missile defense, it's likely a bit more complicated than that. Putin most likely wants out of the CFE treaty so he can retain Russian bases and troops in Moldova and Georgia, supporting post-Soviet ethnic Russians who still reside in Moldova's Transdniestr and Georgia's Abkhazia regions.

Under CFE, Russia would have to close the bases and withdraw troops. But keeping a presence is important to protecting Russia's soft underbelly, retaining a regional power base, and influencing Moldova and Georgia -- and their pro-Russian secessionist movements.

Russia also sees other treaty problems: new U.S. training bases in Romania and Bulgaria, which Putin views as an additional "5,000 American bayonets" deployed against Russia, and the Baltic states that haven't signed on to the CFE's 1999 modified version.

The Kremlin may also consider CFE implementation as political leverage against the likelihood of Kosovo's independence from Russia-friendly Serbia, which the U.S. and Europe support -- and Russia, naturally, opposes.

Arms Bazaar

Today, Russia has the dubious honor of being the world's largest arms supplier to the developing world. Indeed, Moscow is the world's second-biggest arms exporter overall, following the perennial leader, the U.S. Moscow's client list is disturbing. For instance, Russia signed weapons contracts with Iran for the Tor M-1 (SA-15) air defense missile systems, valued at $1 billion. It's also upgrading Iranian Su-24 and MiG-29 aircraft and T-72 tanks.

Of course, although not a weapon per se, Moscow has also been building a $1 billion nuclear reactor for Tehran at Bushehr since 1995, which could be a key element of an Iranian nuclear weapons program if completed. Fortunately, the reactor project, which was expected to be on line in September, is in trouble. Moscow claims Tehran is behind on payments. But it's more than likely that last-minute Russian insomnia about Iran's nuclear ascendancy is causing the delay.

Russia is also selling weapons to Syria, including the SA-18 air defense system. Purchases total $1 billion to $2 billion, but a recent comment by a Russian arms firm indicates Damascus and Moscow may be in discussions for the purchase of advanced fighters, too.

In addition, Moscow has sold $3 billion worth of arms to Venezuela, including fighter aircraft with advanced missiles, helicopters and assault weapons. A diesel submarine contract is also in the offing and may be signed this summer.

And don't forget about China. Russia has long been the source of China's most advanced weaponry, including advanced Sukhoi fighters, strategic surface to air missiles, Sovremenny-class destroyers, Kilo-class diesel submarines and cruise missiles.

Moscow has also agreed to cooperate with Beijing's burgeoning space program. Not good news, considering China's desire to challenge the U.S. for dominance in space and its successful anti-satellite missile test earlier this year.

Military Modernization

After years of abject neglect, Russia is again directing significant resources toward its military. Putin sees a strong military not only as a deterrent against provocation or attack, but as means of resisting pressure on its domestic and foreign policies.

Buoyed by oil and gas revenue, Russian defense spending will increase as much as 30 percent in 2007 -- which follows 22 percent and 27 percent bump-ups in the previous two years. Russia has the world's third-largest defense budget at $90 billion.

Russian military planners see strategic and nonstrategic nuclear forces as the key to stability and deterrence. For the Navy, Moscow is modernizing its strategic submarine force with the Bulava submarine-launched ballistic missile. Russia has begun mass production of the Topol-M after a successful spring test. The Topol-M, also known as the SS-27, is a three-stage silo-based -- or road-mobile -- intercontinental ballistic missile with a range of 10,000 kilometers.

Moscow is also building the Iskander-M (SS-26), a short-range tactical missile with a range of 300 kilometers. Some experts believe the missile design may allow the range to be increased to 500 kilometers, in violation of INF limits.

Russia has recently moved into military cyberspace. According to U.S. intelligence, Russia has the world's most "highly-developed, capable and well-resourced [information operations] capability among potential adversaries."

And Russian intelligence operations are at Cold War levels once again, according to the FBI. Although always fascinated with "inside the Beltway" political gossip for their Kremlin taskmasters, Russian spies are also targeting military-related high technology.

The Energy Weapon

Unbeknownst to most, Russia is the world's largest producer of natural gas (ahead of Qatar) and second largest producer of oil (after Saudi Arabia). Indeed, Russia may have the world's largest aggregate carbon-based energy reserves.

Russia's energy boom days have allowed Moscow to pay off its international debt, build up the world's third-largest foreign currency reserves and establish a $50 billion domestic stabilization fund.

But there's a dark side. Energy today is, arguably, what the Red Army was during the Cold War: the main source of Russia's influence and strength. In fact, Vice President Dick Cheney called Russian energy supplies "tools of intimidation and blackmail."

With record energy prices and demand anything but softening, Moscow has thrown its weight around by nationalizing domestic resources, cutting supplies, ending subsidies or raising energy prices to even former Soviet republics such as Ukraine, Belarus and Moldova.

Russia holds U.S. ally Europe at risk, too. Europe gets 50 percent of its natural gas and 25 percent of its oil from Russia. These percentages are only expected to grow. Hungary and the Czech Republic are already completely dependent on Russian gas.

To minimize free-market forces and maximize its energy muscle more broadly, Russia is also promoting a natural gas cartel along the lines of the Organization of Petroleum Exporting Countries. For instance, Russia, Qatar and Iran together possess 60 percent of the world's natural gas. Other countries, including Hugo Chavez's Venezuela, have expressed an interest in joining such an exclusive club, too.

In fairness, the U.S.-Russian relationship hasn't been all bad news. Moscow has been helpful -- from time to time -- on North Korean and Iranian nuclear issues, agreeing to limited, targeted sanctions at the United Nations Security Council over the past year. Moscow was also supportive in the days following Sept. 11 on counterterrorism. But since then, it's pushed (along with China) for the closing of U.S. bases in Uzbekistan (succeeded) and Kyrgyzstan (nearly succeeded), hindering U.S. operations in Afghanistan.

But in the end, Moscow sees a unipolar world dominated by Washington as a threat to its national interests -- and its pride. The Kremlin is clearly willing to stand up for itself, despite White House objections. Even a newly elected Russian president in March will likely hew closely to Putin's world view -- a view that is not centered on the East or West but is multipolar in orientation and firmly grounded in raw Russian national interests.

Although Putin may not be revanchist in terms of territory, he is revanchist in terms of regaining Russia's clout and significance as an international player. Putin sees America in decline and Russia's star on the rise -- again.

Although Russia won't directly position itself as a foe to the U.S., it won't position itself wholly as a friend, either. Managing relations with Putin's Russia won't be easy -- by any stretch of the imagination. Indeed, as the Director of National Intelligence said in February testimony before Congress: "Russian assertiveness will continue to inject elements of rivalry and antagonism into U.S. dealings with Moscow."

The U.S. and Russia can both benefit from a cooperative relationship. Neither capital benefits from a deeper freeze in already chilly ties. But there will be issues of critical importance on which Russia won't align itself with American interests.

While attractive, taking a hard line with Russia has down sides. It could drive Moscow into Beijing's orbit and create a powerful anti-American bloc that would span the breadth of Eurasia.

Russia and China are already expected to hold joint military exercises in August. These maneuvers, ostensibly under the Shanghai Cooperation Organization, would follow the unprecedented ones held in the summer of 2005.

Moreover, U.S. policy should be crafted in a way that doesn't fully alienate or isolate Russia, foregoing the possibility of any cooperation on critical issues such as terrorism, missile defense, nonproliferation or energy security, among other issues.

The important thing is to see Russia with a sober eye. It's not a bury-the-West Russia, but then again, it's not a make-nice-with-the-West Russia, either.

It's Putin's Russia: a country bound and determined to be front and center on the world stage once again.

Peter Brookes is a columnist for The New York Post, a Heritage Foundation senior fellow and author of "A Devil's Triangle: Terrorism, WMD and Rogue States."