Five Pakistan-based "most dangerous bad guy groups", including Lashkar-e-Taiba (LeT) responsible for the 2008 Mumbai terror attack, pose a critical threat in war-torn Afghanistan, says a top US official. "Of course, Afghanistan and Pakistan have always been closely related," US special representative for Pakistan and Afghanistan Richard Holbrooke told "Charlie Rose" on PBS. "From the day Pakistan became independent they've had a bad relationship." "And now we're in a situation where the sanctuary for the Taliban in Pakistan poses the most serious of all hurdles to our objectives in Afghanistan, and also endangers our national security," he said. While the main US enemy is Al Qaeda lurking "across the border in the tribal areas of Pakistan," Holbrooke said "there are about five of our most dangerous bad guy groups all grouped in this area in Pakistan where the floods are going on now." Besides Al Qaeda, he identified the bad boys as Afghan Taliban, the Pakistani Taliban, "the infamous Haqqani group" and LeT "a group that the Americans don't pay any attention to...but the Indians sure pay attention because it is the LeT who attacked Mumbai in December of 2008." "All based in Pakistan and they're all based in an area roughly the size of California in the tribal areas," Holbrooke said stressing the need "to retain the residual capability to strike at these groups while we build up the Afghan security forces" as the US draws down in Afghanistan. US recognized that Pakistan and other countries, particularly India and China, have legitimate security interests in Afghanistan, he said. "And this opened up the door to a very sustained strategic dialogue with the Pakistanis." "There are other countries who are having similar dialogues with (the US) but not perhaps at this level and the two I want to single out are India and China because they also have legitimate roles in the area," Holbrooke said Asked if Pakistani spy agency ISI (Inter-Services Intelligence) still has a relationship with the Taliban, Holbrooke parried saying the documents leaked by WikiLeaks "allude to a pattern which has been well-discussed, a pattern which has concerned us, that we've discussed with the Pakistanis repeatedly." Pressed on the issue, Holbrooke said: "We have continued to work with the Pakistanis to get them to work with us to do something about the Taliban in the sanctuaries." "They have worked with us in regard - remember the five groups I mentioned earlier. They've worked with us closely on going after the Pakistani Taliban."