President Obama's decision to reverse 65 years of U.S. nuclear weapons policy and drop most of the nation's deterrence capacity has alarmed critics who say they fear that the United States will now be more vulnerable to attack from would-be nuclear nations.

"I'm deeply concerned by some of the decisions made in the Nuclear Posture Review and the message this administration is sending to Iran, North Korea, and non-state actors who may seek to harm the United States or our allies," Rep. Michael Turner, R-Ohio, the ranking member of the House Armed Services Subcommittee on Strategic Forces, said in a written statement. "By unilaterally taking a nuclear response off the table, we are decreasing our options without getting anything in return and diminishing our ability to defend our nation from attack."

The White House nuclear strategy review released Tuesday concluded the Obama administration will narrow the circumstances in which the U.S. might launch a nuclear strike, will forego the development of new nuclear warheads and will seek even deeper reductions in American and Russian arsenals.

In presenting the results of the administration's policy review, Gates said a central aim was to reduce the role of nuclear weapons in U.S. defense strategy.

"If you look at history, and the time after the Cold War, it was a great deterrent for the Soviet Union when it came to preventing them from invading eastern European countries, for example. What you see here is part of what is rather disturbing pattern where the Obama administration continues to take away capabilities that the U.S. needs in its arsenal," she said.