However, as the Vietnam war intensified and he became personally responsible for increasing US troop levels from 500 advisers in 1962 to nearly half a million when he relinquished his position in 1968, McNamara become utterly disillusioned with the conduct and the goals of the conflict. But by then the US commitment was total and it would be nearly another seven years and close on 60,000 American dead before his government realised that this was an extension of their military might too far. 

His memoir published in 1995 outlines his thoughts on why he so radically changed his thinking and gives 11 lessons to be learned from the Vietnam experience. For today’s foray into Afghanistan ever single one is still relevant, unfortunately for those involved on the ground, few if any of these lessons seem to have been learned. 

We misjudged then — and we have since — the geopolitical intentions of our adversaries … and we exaggerated the dangers to us of their actions.  

If the reasons for fighting in Afghanistan are to defeat al-Queda and their campaign of global terrorism then as a strategy this has to be misplaced. Since the 2001 intervention there has not been one international terrorist attack organised from Afghanistan. Al Queda has simply moved to Pakistan, east and north Africa. 

We viewed the people and leaders of South Vietnam in terms of our own experience … We totally misjudged the political forces within the country. 

Although they do not have the almost universal support of large proportions of the population the Vietcong undoubtedly did, the Taliban still have major support in Afghanistan, they are not a spent force politically and are unlikely to be any time soon. Until this is accepted and they are brought into the political process, just as other terrorist organisations have, such as the IRA, this is unlikely to change. 

We underestimated the power of nationalism to motivate a people to fight and die for their beliefs and values.  

Although the Taliban often present this conflict as a Jihad or Holy War against the infidel invader, it is in many Afghan eyes a fight to defend their homeland against a foreign invader. For a significant mass of Afghanis this is a territorial invasion by foreign aggressors. Just look briefly at the UK or Russia’s past involvement in the region. The first Afghan War in 1839-42 saw one of the worst catastrophes to befall the British Army when a garrison of 5000 soldiers, women and children under Major General William Elphinstone were massacred on the retreat from Kabul. After another two largely unsuccessful British incursions, the Russians then tried for a decade from 1979 to impose their will, with more than half a million soldiers occupying the country, only to end in inglorious and bloody failure. Afghans have proven time and time again they will fight to protect their territorial integrity. 

We failed then — and have since — to recognize the limitations of modern, high-technology military equipment, forces, and doctrine. 

IED or improvised explosive devices, the cause of more than 80 deaths of UK troops so far, do not fear unmanned ground attack bombers controlled from 10,000 miles away. As one UK combatant was quoted: ‘We are carrying 100kg of kit in 40 degree heat trying to chase insurgents wearing nothing but a robe, a pair of sandals and carrying an AK 47.’ Better equipment does not guarantee success, the UK currently has around 9000 troops on the ground to keep control of their main area of operations, Helmand, an area almost as big as Scotland. There can never be enough boots on the ground to control territory without local goodwill. 

After the action got under way, and unanticipated events forced us off our planned course … we did not fully explain what was happening, and why we were doing what we did.  

Such goodwill is hard to foster when the mission goals are so vague. UK forces currently find themselves under mission creep. The initial reason given by the international community for UK and coalition troops’ involvement was to prevent al-Queda using Afghanistan as a safe haven for terrorism that could threaten Britain and the rest of the world. This then changed to reconstruction, rebuilding after years of warfare making Afghanistan a safe and stable country. Part of this task was a push against heroin warlords to stop the supply from the world’s biggest supplier.  This has singularly failed with Afghanistan still producing more than 90% of the world’s heroin.

The Uk and coalition forces mission has now spread to providing security for the forthcoming elections, nation building. Opposition to this has turned the expedition from a policing action into a full scale shooting war with no definable exit strategy. 

We did not recognize that neither our people nor our leaders are omniscient. Our judgment of what is in another people's or countries best interest should be put to the test of open discussion in international forums. We do not have the God-given right to shape every nation in our image or as we choose.  

Perhaps the most poignant of McNamara’s observations. Today the west still seems to be trying to impose its vision of democracy and values where it is questionable if they are wanted.  Afghanistan has no traditions of democracy. To try and change this overnight is folly, if Afghanistan is to take its place in the modern world, then like Vietnam the will of the people must decide, whether this journey is satisfactory to the west or not. A point only realised by McNamara after America was in way too deep. His remaining five points are all as pertinent now as when the last Huey scrambled the remnants of US influence off their embassy compound in April 1975.