The United States was well into the surge at this point; between NATO forces and Afghan forces, there were hundreds of thousands of troops to resupply, all of whom had relied on the routes through Pakistan. The need to find alternative routes by land and air—including through Central Asia—ended up costing the Americans about $100 million per month more than the previous arrangement. Many feared that while this worked to get supplies into Afghanistan, it would not be sufficient to get massive amounts of war materiel out of Afghanistan when the United States and NATO withdrew. Consequently, the U.S. government hoped that Pakistan would reopen the ground routes. But it turns out that weaning itself off them was not such a bad option after all.

I argued at the time that Americans should not fall for the cheap ground transport solution Pakistan seemed to offer, in part because what America later spent on air supply was cheaper than the so-called Coalition Support Fund payments they paid Pakistan to help guarantee the use of those routes. Moreover, having kicked the cheap ground supply habit, the United States could be in a better position to do what it needed to do if it wanted to win: Put real and costly pressure on Pakistan for continuing to support the Taliban, which was one of the principle reasons for the U.S. inability to prevail in Afghanistan.

Arguably, America is in an even better position now than in 2011, because it only has about 14,000 troops in Afghanistan compared to 90,000 or so in 2011 (of a total of 132,000 NATO troops). America can certainly sustain this through air shipments, especially if it’s pocketing savings by not paying Pakistan the nearly $1 billion a year in Coalition Support Funds, among other funding streams.

But Pakistan has aces in sleeve.

Pakistan now says the alliance is over—and good riddance. Foreign Minister Khawaja Muhammad Asif complained that “This is not how allies behave.” He is absolutely correct: U.S. allies do not take its lower and middle-class taxpayers’ hard-earned money and hand it over to enemies such as the Taliban, the Haqqani Network, and Lashkar-e-Taiba.

Asif went on to offer the usual protestations that Pakistan’s military operations have cleared Pakistan of sanctuaries for these groups to hide in. But if there were such scoundrels on Pakistan’s territory, he said that if Pakistan went after them, “then the war will again be fought on our soil, which will suit the Americans.”

What is not clear in Asif’s statement is what Pakistan will cease doing. (We know for certain that it will not cease supporting the Taliban, the Haqqani Network, or Lashkar-e-Taiba.) Will Pakistan do as it has done in the past: Close the ground resupply routes? Will it escalate and close down its air space to American resupply flights? If that happens, what will the Trump administration do? Will it consider this action to be an act of war?