The SAS are on a policing mission. The people and country they defend will often appal us. They will seem indefensible.

The SAS are no more likely to "win" than our Police are to "win" in Manukau, if we judge winning by reaching a state where force is no longer needed. Nor is the war they are fighting any more "just" than our Police battle to protect the properties and rights to live in peace of bottle store owners and brothel keepers and liars and tax avoiders and adulterers and cheats on their child support payments, alongside innocent schoolchildren and their mothers.

The SAS are fighting because our leaders, who have more information than us, and who we hope can therefore make a better overall assessment of our interests, believe that the SAS commitment will be to our nation’s advantage. Possibly our warriors will contribute to our long term safety from ruthless enemies, by continually disrupting  those enemies in their homelands. Most peoples at most times have found it advantageous to conduct fights away from home in the enemy’s territory, if fight we must.

There can be some anciliary benefits from putting our people in harm’s way.  Without real action from time to time armed services can’t stay tuned up, or confident of their capacities. They volunteer to be warriors so the moral burden on our leaders may not feel quite as grave as it does with conscripts. Special services probably need action with its risks to keep recruiting the right people. None of these anciliary benefits are of course sufficient reasons.

But the needs of our allies can be. If we as a people childishly demand that our forces should be deployed only in holy wars to defend saints menaced by wicked men, we will perish. Because if we will only allow our soldiers to shed the blood of people who are unremittingly evil they will never get their weapons out of their armouries. And if we only help those who share our values we will be on our own.

It is harder to fight well without an inspiring and  obvious noble cause. Pursuing geopolitical tactical advantage is never as noble as fighting to keep an enemy from our beaches, or installing democracy or upholding freedom. So we should doubly honour our volunteers in Afghanistan, and when they return. For volunteering alone we owe them honour. Never again should we allow what the left of my generation did to the returning Vietnam veterans.

For the feeling of righteousness most citizens crave to justify this commitment we’ll have to fall back on seeing evil ideology taking knocks, even if none of our blows are fatal to it, and even if, as the British commander has said, it could still be going on in 40 years.

In Afghanistan we owe to our troops everything they need for effectiveness. They should lack nothing that would reasonably reduce casualties to the minimum consistent with their mission. We should honour them whatever the outcome of their efforts. We should honour them by protecting them from the lawyers now crawling over our armies (but of course not those of our enemies) looking for breaches of dumb rules of engagement.

And above all we should insist that all our politicians show respect to our service people for courage and professionalism, without requiring us all to pretend that we agree with or "believe in" the mission of the side we are on.

Washington Post columnist Diana West states the chances of long term success succinctly

"An infidel nation cannot fight for the soul of an Islamic nation — a truism that, in a more rational (non-PC) world, might bring surge enthusiasts to their senses."

I agree with her. I do not "believe" we can demand a final victory from what our troops will have to do.

But policing is dangerous, honourable and essential work for all that. So lets hope New Zealanders will find the spirit to give our SAS and those they fight alongside that honour by wholeheartedly supporting them for as long as they are there, even if the cause is murky and dark.