At this week's G-20 summit in London, President Obama met with Russian President Dmitry Medvedev for the first time. The two men share the burden of improving much-frayed relations between their two nations.

They agreed to launch negotiations for a Strategic Arms Reduction Treaty (START) and reexamine Russia's accession to the World trade Organization. The two countries will explore cooperation on Afghanistan and Iran, but agreed to disagree on ballistic missile defense. And Mr. Obama announced he will visit Russia in July. All positive-looking signs.

Many Europeans, especially the Germans, are swooning over Obama-Medvedev pictures that marked the event. The notion of pushing the "reset " button to begin a new era of harmonious relations between the two states is particularly lauded. To many, though, it's déjà vu.

In the 1970s, strategic arms talks between Leonid Brezhnev's Soviet Union and a US reeling from the debacle in Vietnam were a part of the era of détente and "peaceful coexistence." It ended ingloriously, when Soviet tanks rolled into Afghanistan in 1979. And all of Jimmy Carter's pining for peace or shuttle diplomacy couldn't put the broken dream back together again.

Thirty years later, the Nixon Center and the Belfer Center of Harvard University issued a report that tried to set an upbeat tone for US-Russia rapprochement. This may have been guided by the authors' formative experiences of another era. It's important to remember that this is not your father's Russia - neither the geriatric Brezhnev regime of the 1970s, nor the USSR in terminal decline under Mikhail Gorbachev in the late 1980s.

Today's Russian leadership is younger and tougher. It is increasingly anti-American, and continues to aggressively challenge its neighbors' sovereignty. It questions former vassals' sovereignty by opposing ballistic missile defense in Poland and the Czech Republic, or preventing Georgia and Ukraine from joining NATO. Moscow also wants to neuter or dismantle the North Atlantic Treaty Organization (NATO) and the post-Bretton Woods economic system.

Moscow's calls for a new pan-European security architecture should give Obama pause. The concept would abolish NATO and weaken the human rights jurisdiction of the Organization for Security and Cooperation in Europe (OSCE). Moscow proposes national armed forces to be deployed on a "common perimeter" and a "demilitarized zone" inside the perimeter. The scheme is a transparent effort to restrain America's influence.

Beyond Europe, Russia's rulers are obsessed with "multipolarity." They appear to want a world order in which Russia, China, Iran, Syria, and Venezuela form a counter-weight to the United States. This is a broad global agenda at odds with vital US interests.

Washington and NATO's desire to cooperate with Moscow is understandable in view of the ongoing crisis in Afghanistan and Iran's missile and nuclear programs. After the "Yankee Go Home" announcement by Kyrgyz President Kurmanbek Bakiev, Moscow offered the US use of its cargo planes and air space to resupply Afghanistan. It was Tony Soprano geopolitics: "Use my dumps and my trucks - otherwise you can't do business in my neighborhood."

The Kremlin continues to call -- as it has since the St. Petersburg Economic Summit in 2007 -- for revising the global economic system. In the lead-up to the G-20, it proposed creating a supranational reserve currency to replace the dollar as the global standard.

While the two leaders have their hands full with economic and security matters, rule of law should hold a prominent place on the agenda for their next meeting. A healthy legal system is necessary to protect the rights of foreign and domestic investors and to facilitate the development of civil society and human rights.

Russia's rule-of-law track record was abysmal under communism. Medvedev appears to want to turn the fight against corruption into a personal crusade, so there may be a change for the better.

Medvedev should be encouraged to demonstrate his commitment by apprehending those who ordered the murders of Anna Politkovskaya (a fearless journalist), human rights lawyer Stanislav Markelov, and other dissidents. On the trial of Mikhail Khodorkovsky, a former oilman, which has become a travesty of justice, he can bring closure and release Mr. Khodorkovsky from jail through an acquittal, suspended sentence, or a presidential pardon.

Above all, the Obama administration must remain realistic in its dealings with Moscow. It must keep its eyes open, following Russia's actions on the ground, examining the mindset of its foreign policy and security elites, and their efforts to undermine what they view as a US-led international security and economic architecture. Haste is ill-advised, as the Obama administration has not yet completed a comprehensive assessment of US-Russian relations, has not defined its objectives in Russia and Eurasia, and has not completed key personnel appointments. All this is overdue.

Meanwhile, the Obama administration should use its political capital to maintain and expand transatlantic unity at the Friday and Saturday NATO summit in Strasbourg, France, and Kehl, Germany.

In parallel to the START negotiations, the US should propose a mechanism for regular consultations on Russia among the allies. Obama should also encourage America's European allies to diminish dependence on Russian gas and diversify their sources of energy. The administration should maintain European missile defense plans despite the recent setbacks in the Czech Republic. In talks with Russia, the Obama administration should support Ukraine and Georgia's territorial integrity.

If Russia reconsiders its anti-American stance, the US should be prepared to pursue matters of common interest, such as the recent agreement on military supplies to Afghanistan and the strategic-weapons-limitations agreement. Obama is rightly prepared to offer real incentives, such as US support for Russian entry into the World Trade Organization, and should support for repealing the obsolete, trade restricting Jackson-Vanik Amendment of 1974, and resubmission to Congress of the 123 Nuclear Agreement, which would allow US nuclear reactor waste processed by Russia and earn billions of dollars a year doing that.

The US can explore Russia's willingness to rethink its relationship with Iran and prevent it from going nuclear in the near future.

Yet Washington should not bargain away the independence and sovereignty of countries in Eurasia, dismiss concerns over human rights and rule of law in Russia, allow Moscow to rewrite the geopolitical map of Europe with its new "European security concept," or acquiesce to a new global economic architecture. This is not the time for naïveté.

Ariel Cohen, Ph.D., is Senior Research Fellow in Russian and Eurasian Studies and International Energy Security at the Allison Center of the Katherine and Shelby Cullom Davis Institute at The Heritage Foundation.