But while we can never predict where events will take us or the unavoidable bills we will have to pay as a consequence, we must confront the ghastly truth of Labour's legacy.
If Iran becomes a nuclear weapon state it is the end of non-proliferation as we know it. If Iran gets a nuclear weapon you are likely to see Saudi, Egypt and other countries follow suit and we will bequeath to the next generation a nuclear arms race in the world's most unstable region.
New Labour was the most short-sighted, self-serving, incompetent, useless, and ineffective government that Britain has ever known. Make no mistake, Labour's economic policies were a national security liability.
There is a difference between a military mission and the aspiration for the long-term plans for the country. What we want is a stable enough Afghanistan, able to look after its own security so we can leave without the fear of it imploding... But let's be clear - it's not going to be perfect.
We are not in Afghanistan for the sake of the education policy in a broken 13th-century country. We are there so the people of Britain and our global interests are not threatened.
We can't afford to see Afghanistan roll backwards into a failed state that could become a base from which terrorist campaigns can be launched anywhere in the world.
