If sequestration becomes a reality in January 2013, the Department of Defense (DOD) will cut another $500 billion from an already slashed defense budget. These cuts are likely to negatively affect many American allies – especially the United Kingdom.

Here are two programs that London should watch carefully:

1. The Short Take Off and Vertical Landing (STOVL) version of the Joint Strike Fighter (JSF). Defense Secretary Leon Panetta indicated that the DOD could not afford to exempt major programs from defense cuts resulting from sequestration – specifically mentioning the JSF. Furthermore, a House Armed Services Committee report published last year stated that sequestration meant the “likely elimination of the STOVL variant of the JSF.”

The Royal Navy depends on the survival of this program, and its on-time delivery, in order to reintroduce its carrier strike capability in 2020. The British government scrapped plans to install catapults and arrester gear on its new carriers when cost estimates increased from £350 million to £2 billion in less than 12 months. Consequently, with the whole Harrier fleet now decommissioned, the U.K. will not have a carrier strike capability without the STOVL variant of the JSF. Clearly, sequestration puts this at risk.

2. The Ohio-class replacement submarine—especially the development of the Common Missile Compartment that is critical for the next generation of the U.K.’s nuclear deterrent. As part of Obama’s initial defense cuts, the in-service date of the Ohio-class replacement was delayed by two years. It is too early to tell if the delay will impact on the timely delivery of the Common Missile Compartment.

In addition, nobody knows what sort of impact sequestration could have on the program. Unlike the STOVL variant of the JSF, there is no threat of a total cancellation. However, the concern for the U.K. is with any further delays to the program, which could impact the future development of the U.K.’s own nuclear deterrent replacement.

In Britain, before the Conservative Party entered office, nobody would have imagined that the U.K. would end up cutting its sole aircraft carrier, its whole Harrier fleet, 40 percent of its main battle tanks, and 20,000 soldiers – all in the name of deficit reduction. Everyone wants to believe that his own program is safe from cuts, but the truth is that nobody knows what will happen. London should be prepared for the worst-case scenario.