On 10 February 1975, the SECDEF issued a study directive for examining feasible degrees of the Air Force's Missile X (MX)-TRIDENT II commonality, potential performance degradations, and resultant cost advantages associated with the various degrees of commonality. It was also during this time frame that the TRIDENT II Characteristics Study was underway. The Navy's perception of the specific military requirement for TRIDENT II were in a state of flux. Hard-target capability appeared to be in the SECDEF's mind but no firm nuclear weapons employment policy appeared. In fact, none was likely until MX commonality and possible improved accuracy alternatives were resolved. In line with this, the SECDEF, on 23 July 1975, deferred TRIDENT II operational availability date (OAD) to 1987.

On 3 May 1976, the Deputy SECDEF wrote to the SECNAV, outlining the desirability of SWS having both survivability and a wide range of capability. The TRIDENT submarine, having invulnerability as well as the potential for increased throwweight, "encourages consideration of options to expand our SLBM capability against the full spectrum of the target system." The Navy was therefore requested to develop an overall TRIDENT II missile development plan for increasing the "utility" of the FBM system for IOC in the 1980s.

In the meantime, in 1976 Congress, for the second consecutive year, denied the Navy's request for research, development, test, and evaluation (RDT&E) funding to initiate TRIDENT II conceptual development.

On 16 August 1976, when the SECNAV responded to the Deputy SECDEF above-mentioned guidance outlining TRIDENT II conceptual goals for an all new D5 hard-target systemhe noted that only minimal in-house effort could be undertaken in FY 1977. But assuming that TRIDENT II funding would be available in FY 1978, it still appeared feasible to plan for a 1987 IOC. Meeting such a schedule, however, would definitely be contingent upon DoD waiver of normal acquisition procedures.