The conference report stipulates that no funds may be spent on the retirement or dismantlement of the 18 Trident SSBNs unless START II enters into force or the president certifies that four achievable conditions have been met. Specifically, the president must certify that the Trident force reductions will not threaten the effectiveness of the U.S. nuclear deterrent, will not provide a disincentive for Russian ratification of START II or negotiation of future arms control measures, will not interfere with U.S. abilities to carry out its nuclear war plans (known as the SIOP) and will not prevent the United States from "uploading" its nuclear delivery systems should new threats arise.
Once this certification has been transmitted to Congress, the United States can maintain 16 SSBNs for the first 240 days and 14 SSBNs thereafter. The conference report includes $13 million to preserve the option of converting the four retired boats to a conventional role. Despite the exemption for the Tridents, the United States is still required to stay at START I force levels (6,000 "accountable" warheads) until START II comes into effect.