LISBON — Russia agreed Saturday to cooperate with NATO on erecting a U.S.-planned antimissile network in Europe as part of what was described as a new era in security relations between the former Cold War enemies.
The accord, announced at a NATO summit in Lisbon, symbolized a conclusion by the United States and its main European allies that Russia is not a threat to be protected from, but a potential ally in girding the continent against possible ballistic missile attacks from Iran or elsewhere.
"We see Russia as a partner, not an adversary," President Barack Obama said, hailing the NATO-Russian accord.
President Dmitri Medvedev warned, however, that Russia's cooperation must be "a full-fledged strategic partnership between Russia and NATO" and not just a nod in Moscow's direction to spare Russian feelings while Europe tends to its own defenses in tandem with the United States.
"Otherwise, it's a no-go," he said at a news conference here. "Everybody's clear that the missile defense system will be useful only when it is universal. I'll be blunt with you, we need to sort it out."
The NATO secretary general, Anders Fogh Rasmussen, said NATO countries and Russia will immediately revive cooperation on theater missile defenses for troop protection and launch a joint, six-month analysis of how Russia could be part of the broader, Europe-wide coverage being planned for deployment in the years ahead.
"This is of real political importance," Rasmussen said.
Earlier troop protection cooperation, from 2002 to 2008, included an attempt to define similar terminologies and several joint exercises, a senior NATO official said. But the cooperation, under the aegis of a forum called the NATO-Russia Council, was suspended after Russia invaded secessionist Georgian territories in the summer of 2008.
The accords announced in Lisbon marked a resuscitation of the council but also, according to Rasmussen, took the prospect of security cooperation with Russia to an unprecedented level, perhaps including integration with the European missile defense network.
In that vein, Russia also agreed to increase cooperation with the NATO allies in combating terrorism, narcotics smuggling and piracy. In addition, it promised to allow increased transit of non-lethal NATO equipment and supplies across Russian territory to and from the U.S.-led war in Afghanistan.
"This is indeed a historic event," Medvedev said, joining the chorus of European leaders saluting what they called a milestone. "I also use the term historic today, meaning we have traveled a long distance."
The antimissile coverage would be anchored by a U.S. land- and sea-based deployment, reconfigured by Obama from earlier plans devised under the Bush administration.