LONDON (Agencies) - US President Barack Obamas attempt to clarify his July 2011 deadline for a US departure from Afghanistan has resulted in more confusion and will dilute Pakistans commitment to fighting the Taliban, Republican Senator John McCain has told The Daily Telegraph. Sen McCain, who has led criticism in Washington over the Presidents most controversial element, said senior administration officials had only contradicted each other when trying to explain how the timeline for the beginning of a US troop withdrawal would work in practice. Since the President made his speech, we have not had further clarification, in fact we have had further contradiction, he said. On the one hand, we see the Secretary of Defence and the Secretary of State say its just a flexible date, then the Presidents spokesperson says its chiselled in stone and he has the chisel. Theres a real contradiction there. The muddled messages, after three months of deliberations and nine top level White House meetings, has left many in Washingtons foreign policy community aghast. Obama said that the 30,000 additional US troops, combined with extra Nato forces - now likely to number 7,000 - will allow us to begin the transfer of our forces out of Afghanistan in July of 2011. He stipulated that the pace and timing of withdrawal was dependent on conditions on the ground, but the following day, under intense questioning from McCain at a Congressional hearing, Defence Secretary Robert Gates said the initial pullout date itself would be reviewed in December 2010. Sen McCain was concerned that the Pakistanis in particular may be caused to weaken their support for the plan, and keep their options with the Taliban. The most important point being missed here is what will be the commitment of the Pakistani military who we all now is very much divided right now? What does it say to a General that works for Kayani [the Pakistan Army Chief] in the ISI [the security agency] who is now saying 'they [Americans] may well be out of the neighbourhood again and we have to stay in the neighbourhood so we have to accommodate. Sen McCain, a foreign policy veteran whose opinion carries great weight in Washington, recalled that after the CIA had helped the Afghan resistance repel the Russian occupiers in 1989, Washington abandoned Afghanistan completely. It accelerated the countrys spiral into a civil war which led to the advent of the Taliban under the ISIs tutelage, he alleged. The defeated candidate in last years presidential election, Sen McCain said he believed Obamas strategy could work. I want to help him succeed. I dont want us to fail, he said.