John Thune actually said...

"the decision to agree to a limit of 700 deployed strategic delivery vehicles did not result from a change in the security environment"

"President Obama asserted in his NPR that the United States could deter potential adversaries and reassure allies with a 'reduced reliance on nuclear weapons.'"

"how do we know the administration will pursue these programs?"

"Russia will threaten to withdraw from the treaty should the United States expand its current missile defense capabilities."