In the confidential 66-page report, authored by General Stanley McChrystal, and excerpted in The Washington Post, the commander argues for a rapid troop increase and a shift away from equating the success of the campaign with the number of Taliban killed.
More specifically, the report says "success demands a comprehensive counterinsurgency campaign" that refocuses on protecting and winning support from ordinary Afghans and diminishes perception of the Nato force as an occupying army.
Gen McChrystal goes on to say the task of the International Security Assistance Force (ISAF) has been made all the more difficult by rampant Afghan Government corruption and a hesitation by civilians to side with the authorities for fear that the Taliban might actually win - not an unreasonable position given that the general himself warns if the Taliban is not driven back by fresh commitment of resources within a year, then the war will be unwinnable.
New Zealand's contribution of 71 SAS soldiers is tiny when compared with the additional 21,000 US troops already approved by President Barack Obama this year. That cohort raises to 68,000 the total US troop commitment alongside the 38,000 other Nato soldiers, but Gen McChrystal, and other army commanders, evidently see this as insufficient.
Mr Obama is thus far unmoved, appearing to stand by comments made last weekend to the effect that he is reluctant to increase troop numbers - "until I'm satisfied that we've got the right strategy". This division of opinion between politicians and the military is also seen in the UK.
British commanders have argued for a further 1000 to 2000 troops for Helmand province in southern Afghanistan where about 9000 British soldiers are already stationed.
Such an unsettling gulf between military and political wings can only add to uncertainty over what might constitute a "winning" strategy for ISAF, and does little to assuage fears among the British and US public that the war is actually unwinnable; and further, amid such talk as "committing more troops" and "winning hearts and minds", that Afghanistan is not drifting towards a costly and politically combustible Vietnam-style stalemate.
These latest revelations will likely reinforce the doubts of those in this country already convinced the decision to redeploy the SAS to Afghanistan was an unwise move - precisely because of uncertainties over strategy and, as confirmed by the commander's surprisingly frank views, the possibilty of something less than a successful campaign.
The SAS was last in that country in 2006, its third deployment as part of ISAF. Back then, there was greater optimism over the prospects for military and civil success.
Much of that has dissipated as the Taliban has made gains over infamously difficult and inhospitable terrain, but also as the imperfections, not to say corruption, of the much-vaunted "democratically elected" Hamid Karzai Government have revealed themselves - and undermined its legitimacy.
It is evident that New Zealand was placed under considerable pressure to rejoin the effort in Afghanistan - in addition to the successful defence force rebuilding programme in Bamyan. Beyond a perceived moral necessity to "do one's bit", the quid pro quo for such a commitment remains unclear.
This country has limited troop resources, and from a global security standpoint it is arguable that such forces are of greater strategic value in this hemisphere, ready for deployment to localised potential trouble spots such as Fiji, the Solomon Islands and East Timor.
On the eve of his departure for New York, Mr Key said that it had been a hard decision to commit the SAS, and admitted it was entering a "dangerous environment". He said that the SAS was there to help "stabilise" Afghanistan.
Unfortunately, it appears - according to the testimony of Gen McChrystal - that long-held goal is proving increasingly elusive.
