It was not merely the Taleban, the hostile tribes, the bombs, mines and even more hostile terrain that haunted British commanders as they planned their most audacious and complex operation in Helmand to date.

They already knew that carrying a delicate, multimillion-dollar cargo of machinery along 75km (47 miles) of road to the power plant at Kajaki would be beset with obstacles.

Yet they also understood that the plan was fraught with political and military problems at the highest levels. The knowledge left many Nato commanders wondering whether the lives of their men were being risked for the sake of little more than American political expediency.

From the very start, commanders on the ground were concerned about the timing of the operation. Late August marks the culmination of Afghanistan’s fighting season, a period when the maximum number of insurgents are guaranteed to be in Helmand province. Moreover, the British 16 Air Assault Brigade was in the final few weeks of its tour, a time when troops are traditionally preparing to rotate out of the country and see their replacement units safely installed, rather than embarking on new, complicated, risk-laden operations.

Speaking to The Times in Kabul in July, officials involved in planning the operation said that British commanders preferred instead to wait until next spring’s poppy harvest, a guaranteed point of low ebb in the Taleban’s activities, to launch the convoy.

In spite of these misgivings, Nato came under pressure from Washington to secure visible progress in the Kajaki hydroelectric project to safeguard future funding lines before the US presidential elections.

Since 2004 almost $28 million had been spent by the Louis Berger Group (LBG), the American company contracted by the US Government to fix and maintain the Kajaki plant’s two existing turbines and install a third. Overall, the project — including future work such as the addition of a powerhouse and the reconstruction of transmission lines — had a total of $100 million dollars earmarked from USAID, the American development agency.

But the Kajaki project ground to a halt two years ago when British troops deployed in the area and became embroiled in regular clashes with insurgents. The crucial third turbine sat in Kabul and, with no improvement in security, USAID funding lines were under threat.

LBG’s schedule for completing the installation of the third turbine had been set originally for June 2007. As a result of the delays the completion date was reset to September 2008. LBG said that if any part of the critical machinery carried in the British convoy was damaged or destroyed it would take between nine and twelve months to reorder, delaying further installation work on the third turbine until at least 2010.

Better, therefore, they argued, that the British convoy attempted the route this summer, so that any damaged equipment could conceivably be replaced in keeping with the new time-line.

Questions were also raised about strategy. The overarching gambit behind the Kajaki project was to influence locals into supporting the Afghan Government with the enhanced electricity supply. However, insiders pointed out that much of the Kajaki Dam’s existing power output was already controlled and taxed by the Taleban as it travelled though districts held by the insurgents. The installation of a third turbine was thus unlikely to undermine Taleban authority in the short term, and could actually boost it.

When The Times tried to publish a story reporting these concerns among US and other Nato officials, the article was blocked by a Ministry of Defence D notice, on the ground that it would endanger forthcoming operations.

As British troops, dust-covered and exhausted, return from Kajaki having completed the operation, critics of the British mission in Afghanistan should give them the credit they deserve for having successfully completed the most daring, ambitious and complicated operation in southern Afghanistan since they were deployed there.

Equally, however, those claiming that all is well that ends well should remember that the Government allowed its men to be risked in a questionable operation at an especially vulnerable moment, silenced the press in order to do so, and that the long-term implications of the Kajaki operation remain as yet unknown.

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