I say again. If we weren't pouring money down the drain, these commitments would be easily affordable.
And I think you're wrong about public support. The days when isolationism and pacifism had any appeal are long gone. Joe P now likes the idea of bashing Johnny Foreigner, especially in the context of UN approved 'peace enforcement ops'. Remember that the Falklands and Granby both resulted in election victories for the parties in power. Even Labour have realised this, and have ditched unilateralism, and were assiduous in presenting SDR as a re-structuring, not a package of cuts. TV pictures of dead Kosovan children and machete-scarred `Sierra Leonians made these interventions popular. The danger is that we won't intervene somewhere and the public will ask: "Where are our forces? Why aren't they there?"
But spend the defence dollar wisely, scale the Armed Forces to meet the potential requirement and there doesn't have to be a problem.
But if you decide that home defence is enough, then disband everything and just sit tight with Trident!