|Fig. 1: Photo of armed Vanguard-Class submarine in the Trident Program. (Source: Wikimedia Commons)|
Nuclear weapons are an important part of the United Kingdom's defense. Prior, to the latest iteration of the program, the Trident Program, there was Polaris which utilized four submarines between 1962 and 1992. Since 1992 The Trident program has become at the center of the United Kingdom's nuclear defense.
The Trident program it made up of 4 Vanguard-class submarines, one of which is shown in Fig. 1. Each submarine carries eight missiles and 40 nuclear warheads. At all times, one is on patrol, on is just coming off patrol, one is preparing for patrol, and one is undergoing maintenance. According to estimates, each warhead on board is almost seven times more powerful than the atomic bomb dropped on Hiroshima. On top of its power, its distance can also go farther, traveling up to 7,500 miles away at faster than 13,000 miles per hour. The warheads can only be launched by the Prime Minister of the UK. The Prime Minister must send the request to a headquarters where a series of encrypted, coded messages are sent to the submarine to launch. 
The current submarines are expected to require replacements in the early 2030's. It is estimated it will take up to 17 years to replace the submarines so they would require work immediately. The government estimated that the new submarines would have a 30 year lifespan and a cost of ~$38.5 billion. On July 19, 2016 members of parliament voted to renew the Trident system. It was newly elected Prime Minister, Theresa May's first vote in office. 
The Trident Program is an important and vital system to the defense of the United Kingdom. Given it is always at sea, it gives the United Kingdom the ability to strike even if Westminster is completely wiped out. This is why Trident is known as a nuclear deterrent, because given its capacity, it deters other countries from attacking the UK. While nuclear weapons are dangerous and have the potential for lots of destruction, they are important in maintaining current global stability, something the Trident program is a living example of.
© Neil Jain. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 E. Allen and B. Farmer, "What Is Trident? Britain's Nuclear Deterrent Explained," TheTelegraph, 23 Jan 17.
 "MPs Vote to Renew Trident Weapons System," BBC News, 19 Jul 16.