The Defence Secretary came to Faslane to make the case for Britain's nuclear deterrent, announcing £350m of funding for its proposed renewal.
The SNP say it is a waste of cash, and claim that unionists are scaremongering over the jobs that would go if Trident was removed from Scottish waters.
Just the design phase of creating a replacement for the vanguards will cost £3bn but the defence secretary insists Britain can afford it.
However, despite the fact millions are already being spent, a decision hasn't been taken on whether to renew the nuclear programme. The Lib Dems are heading a review of alternatives.
Two years before the final Trident decision is taken, Scots will have already spoken and in doing so decided if Scotland wants to continue being home to Britain's ultimate deterrent.
Scotland Tonight discussed the issue with the leading defence analyst Francis Tusa and Dr Phillips O'Brien, director of the Scottish Centre for War Studies at Glasgow University.
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