"The border with Pakistan is a source of frustration," Marine Corps Maj Gen John Toolan, commander of the 2nd Marine Division and former commander of Regional Command-South West, said.
In a breakfast meeting on Tuesday, Toolan told Defence Writers` Group that during the year of his stay in Afghanistan the Pakistani Army`s 12th Corps was positioned across the border.
The problem is Pakistan has worries of its own and Balochistan, which borders Afghanistan`s Helmand and Nimruz provinces, has its own separatist movement underway, he said.
"The Pakistani military knows, if they start doing things, they could stir up the Balochistan beehive, so they just sit there. And it`s frustrating. Diplomatic pressure on Pakistan is important, but we don`t want to break the Pakistani government," Toolan said in response to a question.
"As a military commander that has to deal with it, I can keep mopping the floor but I can`t turn off the water," Toolan said.
"I can`t stop the flow of lethal aid into Afghanistan. I can interdict it when it gets there. I can`t stop the flow of drugs out of Afghanistan through Pakistan and Iran," he said in another round table with bloggers.
"Those have a significant impact on the environment. And until we make arrangements, until we can get the cooperation of some of the border countries, this problem will persist. Additionally, you know, the drug industry in Helmand province in particular is huge," he said.
Toolan said that there has been movement of illicit items back-and-forth across the rugged Afghanistan-Pakistan border is free flowing. On the Pakistani side, he noted, Taliban forces have "huge caches of IED-making materials.