Long rumored, British officials are now talking openly about abandoning, or at least scaling back, their submarine delivered nuclear weapons arsenal. This is encouraged by the American government, which is pushing global nuclear disarmament. That currently means negotiating reductions in U.S. and Russian nuclear arsenals (to under a thousand warheads each).
Meanwhile, Britain is having trouble maintaining its current armed forces, and is taking advantage of this nuclear disarmament movement to suggest only replacing three of its current four SSBNs (ballistic missile nuclear subs). To understand how this would work, you have to consider the size, and cost, of the British military. The British armed forces have 191,000 on active service. Of those, 38,000 are in the Royal Navy, 109,000 in the Army, 41,000 in the Royal Air Force, and the rest in joint staffs and operations. The annual defense budget is about $58 billion. While the army gets the largest portion of the budget, because most of the money goes to personnel, the navy and air force get most of the procurement money to pay for ships and aircraft.
What annoys the army the most is the continued effort to maintain Britain as a major naval power. The generals can understand the need for destroyers, frigates and submarines to defend the seas that surround the British isles, but they chafe at the nearly $40 billion that is to be spent on building four SSBNs and two aircraft carriers (and their escorts). The SSBNs are also expensive to operate and maintain. Building, operating and maintaining each of those four new SSBNs would cost $1.5 billion a year. To fund this, on a shrinking defense budget, the army is starved for modern combat equipment. This is allowed to happen while thousands of British troops are in combat. Many British officials, including some military ones, are suggesting that Britain not replace any of its four aging SSBNs.
Meanwhile, a year ago, Britain hired an American submarine builder (General Dynamics) to design a Common Missile Compartment (CMC) for Britains next class of ballistic missile submarine (SSBN), which are to begin replacing the current Vanguard class boats in 2022. The assignment specifically mentions that the U.S. Navy will use the CMC for its next class of SSBNs. This makes sense, because Britain buys the ballistic missiles for its SSBNs from the United States. It would be too expensive for Britain to design and build its own SSBN ballistic missiles. Thus the CMC will have to be designed by an American firm, with access to data on the characteristics (especially the dimensions) of future missiles for SSBNs.
Britain and the United States have long cooperated on designing nuclear submarines, especially SSBNs. The U.S. and Britain are designing two different SSBNs. But each sub will have many common features, like the CMC, and that will save a lot of money for both nations. The 18 U.S. Ohio class SSBNs were built between 1979 and 1997. The Ohios were built to serve for twenty years, but that has been extended by at least 15, and possibly 30 years. In the next 5-10 years, work on a new class of U.S. SSBNs will have to begin.
Maybe Britain could offer to crew one of the new U.S. SSBNs, so as not to put highly trained British sailors out of work.