“We are paying a painfully high cost to keep more troops in Afghanistan for longer – with few, if any, benefits. The president’s announcement is a step in the right direction, but he needs to do much more to fulfill his promise to end a war that’s gone on for far too long.”

“As a Bay Stater, I’m proud to have voted to endorse Rep. Markey’s candidacy for the Senate,â€� said Priscilla McMillan, of Cambridge, who is described as an expert on U.S.-Russia relations and one of the group’s board members. “Markey’s courage and far-sightedness in nearly four decades of public service leading the effort for greater control of nuclear weapons and better protection of the environment make him the perfect successor to Senator Kerry.”

Coupled with the nomination of fellow foreign relations colleague Sen. John Kerry (D-Mass.) as secretary of state, Obama has created “a very strong team on arms control,� says John Isaacs, executive director of the disarmament advocacy group, Council for a Livable World.

‘‘What is extraordinary’’ is that the missiles have been deployed even though they ‘‘have never successfully intercepted a test target,’’ Kingston Reif, director of nuclear nonproliferation for the Council for a Living World, said in an e-mail.

“I think there is a great loss for the pro-nuclear weapons defense hawks with the [retirement] of Senator Jon Kyl,� according to Isaacs. “One senator can make a lot of difference when that senator is very engaged, active and a good legislator.�