WASHINGTON — A US Army officer has challenged the claims of American military successes in Afghanistan, saying the war was "going disastrously," according to a media report.The officer, Lt. Col. Daniel Davis, after two one-year duties and travelling 9,000 miles in Afghanistan, has turned a whistle-blower, according to a dispatch in The New York Times. The colonel said the reason he had taken that role was because he had repeatedly seen top commanders "falsely dress up a dismal situation"."And then, late last month, Colonel Davis, 48, began an unusual one-man campaign of military truth-telling," the Times said. He wrote two reports, one unclassified and the other classified, summarizing his observations on the candour gap with respect to Afghanistan. He briefed four members of Congress and a dozen staff members, sent his reports to the Defence Department’s inspector general — and only then informed his chain of command that he had done so. “How many more men must die in support of a mission that is not succeeding?“ Colonel Davis asks in an article summarizing his views titled “Truth, Lies and Afghanistan: How Military Leaders Have Let Us Down.” It was published online Sunday in The Armed Forces Journal, the nation’s oldest independent periodical on military affairs. “No one expects our leaders to always have a successful plan,” he says in the article. “But we do expect — and the men who do the living, fighting and dying deserve — to have our leaders tell us the truth about what’s going on.”Colonel Davis says his experience has caused him to doubt reports of progress in the war from numerous military leaders, including David  Petraeus, who commanded the troops in Afghanistan before becoming the director of the Central Intelligence Agency in June. Last March, for example, Petraeus, then an Army general, testified before the Senate that the Taliban’s momentum had been “arrested in much of the country” and that progress was “significant,” though fragile, and “on the right azimuth” to allow Afghan forces to take the lead in combat.