In a statement, David Wright of the group's Global Security Program said that there are both technical and strategic reasons for reversing the Bush administration's plan to locate parts of the system in Poland and the Czech Republic.
The system is untested and there is no proof it would be effective, Wright said. But plans to install it have enraged Russian leaders, threatening U.S. security by hampering cooperation on important issues like halting Iran's nuclear program.
"President Obama should say no to deploying a missile defense system that offers no security benefits and needlessly provokes Russia," Wright said. "Missile defense is not a magic bullet. Real-world threats require real-world solutions."
Secretary of State Hillary Clinton is expected to discuss the missile shield Friday during a meeting with her Russian counterpart, Sergey Lavrov, in Geneva. It is also likely to be an important issue in April when Obama meets President Dmitry Medvedev for the first time in London.