America will not turn away from Afghanistan; that was the message from Defence Secretary Robert Gates on a surprise visit to Kabul.His trip comes a week after President Obama announced 30,000 more troops would be deployed there. Gates admitted the US mistakenly abandoned Afghanistan after Soviet troops withdrew in 1989. He said: “Our relationship with Afghanistan is a long-term commitment. As President Obama and I have said repeatedly, our government will not again turn our back in this country or the region.” Re-elected amid allegations of rampant fraud in August, the Afghan president Hamid Karzai warned it could be decades before Kabul could pay for its own security. “For a number of years, maybe for another 15 to 20 years, Afghanistan will not be able to sustain a force of that nature and capability with its own resources,” he said. The top US and NATO commander, General Stanley McChrystal, has told Congress that, with the new troops, America and its allies will be able to reverse the momentum of the Taliban within a year.