Afghan President Hamid Karzai said Pakistan had not co-operated on security issues but talks with Islamabad should continue. Earlier in statement Afghan Defense Minister said Rabbani's killer was a Pakistani and laid the blame on the Taliban-affiliated Haqqani network and also accused Pakistan's intelligence agency, the ISI, of involvement - a charge Islamabad denies. *INT*Stephen Cohen is a renowned analyst on South Asian affairs and author of more than a dozen books. He said he was pessimistic that negotiations in Afghanistan could fail and the country would go into a civil war because the US, Afghans or Pakistan have no vision which would make it possible to have a negotiated settlement for Afghanistan. He said "political solution may not be possible because of the tribal culture of Afghanistan and the Ambitions of the Pakistani Generals." Stephen added that America could seek a regional role in Afghanistan which would include India and Iran and the US could play a moderator's role for Pakistan, India and Iran.