WASHINGTON — Leaders of all 28 NATO nations at a Nov. 19 summit in Lisbon, Portugal, agreed to a new strategic concept for the alliance, which includes deployment of a ballistic missile shield to defend all its European territories and could include Russian participation.

NATO and Russia at the summit agreed to cooperate on a joint ballistic missile threat assessment and an analysis of a broader joint missile defense architecture for the future, according to a Nov. 20 NATO press release. The results of the studies are expected to be revealed at a June 2011 meeting of the NATO-Russia Council, the press release said.

The NATO missile shield endorsed in Lisbon will include a system of sea- and ground-based interceptors proposed by U.S. President Barack Obama in September 2009, and the alliance will spend the next seven months drafting an implementation plan that will identify which other systems will a part of the shield, according to a Nov. 20 White House fact sheet.

Afghanistan was a central focus of the summit, where the 49 nations contributing to the NATO-led war effort there agreed to a goal of fully transitioning national security responsibilities to the Afghan government by the end of 2014.

NATO’s new strategic concept — the organization’s first major update in a decade — reaffirms the alliance’s guiding principle that an attack on one is an attack on all. The partners also pledged to deploy new defenses against cyber attacks and restated their commitment to maintaining nuclear weapons so long as these weapons exist elsewhere in the world.

At a press conference before departing Lisbon, Obama highlighted the missile defense agreement.

“Most important, we agreed to develop a missile defense capability for NATO territory, which is necessary to defend against the growing threat from ballistic missiles,” he said.

A U.S. plan to deploy a missile defense system in Europe endorsed in 2006 by then-President George W. Bush was firmly opposed by Russia, which viewed it as a threat to its own nuclear deterrent. The Bush-era plan would have placed long-range interceptor missiles in Poland and a radar system in the Czech Republic capable of peering into Russian territory.

Obama scuttled that plan and proposed a more mobile system that could be fielded sooner and become increasingly capable over the decade ahead. Dubbed the Phased Adaptive Approach, Obama’s plan would station U.S. Navy Aegis ships capable of defending against short- and medium-range ballistic missiles in European waters as soon as 2011 and deploy a radar system in Southern Europe. Land-based interceptors would be placed in Poland and Romania by 2015 and replaced toward the end of the decade by longer-range missiles capable of defeating IBCMs.

The possibility of cooperation between NATO and Russia on missile defense may finally allay tensions that have prevented U.S. ratification of the New START nuclear arms reduction treaty signed by Obama and Russian President Dmitry Medvedev in April. Republicans in the U.S. Senate have expressed concern that language in the treaty’s preamble could limit the United States’ ability to field missile defense systems. The White House is pushing to get the treaty ratified during the current lame-duck session because the Senate will welcome six new Republican members in January who could make it more difficult to obtain the required 67 votes.

Analysts at the Heritage Foundation, a conservative think tank here, applauded NATO’s adoption of the new strategic concept and missile shield, but urged the body to stand behind its deadline of drafting an implementation plan by June 2011. In addition to the U.S. missile defense systems planned for Europe, NATO has development programs well under way with its Active Layered Theater Ballistic Missile Defense system and Medium Extended Air Defense System upon which the European shield can be based, the Heritage Foundation’s Baker Spring and Sally McNamara wrote in a Nov. 24 paper.

“Nevertheless, NATO will need to expand on these existing programs,” Spring and McNamara wrote. “Europe’s contribution to a transatlantic-wide missile defense architecture is about more than hosting U.S. sensors and interceptors.

“As important as the hosting arrangements in locations such as Poland and Romania are to the administration’s Phased Adaptive Approach to missile defense, cooperation should extend to other activities, such as the joint development of missile defense systems, establishing command-and-control systems, and preparing operational plans.”