New Zealand soldiers have been in Bamiyan Province, Afghanistan, for nearly 10 years trying to help the local people.
If nothing else, the deaths of two more soldiers and wounding of six others have underlined the futility of New Zealand keeping troops in Afghanistan much longer.
New Zealand's blackest day during this country's near decade-old deployment in Bamiyan Province has only strengthened the already-compelling rationale for the withdrawal of the provincial reconstruction team which is timetabled for next year.
The top brass in the Defence Force continue to make the obligatory noises about New Zealand troops keeping the Taleban and other "insurgents" in check while local Afghan security forces are readied to take control. But even the military do not sound convinced.
The reason is simple. The facts of Saturday's tragic firefight and a subsequent insurgent attack on Sunday night by rocket-propelled grenades and small-arms fire on New Zealand soldiers in the village of Do Abe speak otherwise - just as they did with the SAS endeavouring to fulfil a mentoring function with Afghan forces in Kabul, the country's capital.
It was especially illuminating yesterday to hear the Prime Minister reveal that - among other new and unspecified self-protection measures - New Zealand troops now have authority to expand the area of their patrols beyond Bamiyan Province to be able to monitor insurgent movements more effectively. Nor did John Key completely rule out the possibility of dispatching more troops temporarily to Bamiyan to enhance the safety of New Zealand personnel in the months leading up to the withdrawal.
All this is a very long way removed from the more innocent days of the provincial reconstruction team's tenure when their role was defined in terms of building schools and hospitals - not fighting battles. The reality is New Zealand is now unwittingly molasses-deep in the stickiest military mess of all - a civil war fought by means of guerrilla warfare.
The weekend attacks sent an obvious message from the insurgents: you have been here 10 years. You can stay for another six months or another six years. It will not make any difference. You are wasting your time.
Only the need for public decorum in the wake of the death and injuries plus deference to the bravery of those caught up in Saturday's ambush stopped New Zealand's politicians basically agreeing yesterday. With the New Zealand flag again at half-mast at Parliament, there was a palpable sense of resignation. New Zealand has done what it can for Afghanistan. It cannot do any more.
To be even more blunt and mercenary, the Afghan deployment has served its foreign policy purpose in helping to rebuild defence ties with the United States. That job done, it is time to go.
In departing, New Zealand has learned the painful lesson reputedly first voiced by Alexander the Great and echoed down the centuries: Afghanistan is very easy to march into but mighty hard to march out of.