Scottish National Party sweep calls U.K. Trident program into question.

• Author: Tadjdeh, Yasmin

* When the Scottish National Party swept dozens of parliamentary seats in the recent U.K. general election, it sent reverberations around the globe.

Scots have historically been wary of the United Kingdom's Trident program, the country's sole nuclear deterrent, which consists of Vanguard-class submarines, Trident II D5 ballistic missiles and nuclear warheads based in Scotland.

The submarines are nearing the end of their service lives and replacements are slated to enter service in the late 2020s. However, U.K. politicians, defense officials and policy experts have been debating for years whether a replacement of Trident is financially feasible and wise in light of security threats around the world.

The U.K. Ministry of Defence has estimated that it would cost between $23.4 billion to $31.2 billion to replace Trident in 2006-2007 prices. Some critics, however, have said the entire lifetime cost of a replacement would top $156 billion.

The Conservative Party--which won a majority of seats in the House of Commons during the recent election --is resoundingly for a replacement, as are some Labour Party members. SNP members, however, have been fiercely against it.

Now some experts say that SNP --with its increased influence after winning 56 seats in Parliament--may push for the dismantling of the program and potentially squash any chance of a replacement.

Nicola Sturgeon, SNP's leader, has repeatedly said the party would never vote in support of a replacement.

"My party does not support the nuclear deterrent and does not support the renewal of the Trident nuclear deterrent," said Sturgeon during a speech at the Council on Foreign Relations in June.

Other SNP party leaders have also publicly decried the program, including Angus Robertson, SNP's Westminster leader.

"The Trident nuclear missile system is unusable and indefensible--and the plans to renew it are ludicrous on both defense and financial grounds. No politician can say with any credibility that they would ever fire nuclear weapons, which would kill civilians massively and indiscriminately and create environmental catastrophe," he said in a statement in April when he served as SNP's defense spokesperson and campaign director.

Sturgeon said SNP would prefer funds from the Trident replacement to instead go toward more conventional defense acquisitions, such as maritime surveillance. She noted that the United Kingdom currently does not have any maritime patrol aircraft and that is an issue...