For seven months, Pakistan has blocked ground convoys from resupplying NATO troops based in Afghanistan – wanting an apology for the deaths of 24 Pakistani soldiers killed in a U.S. strike last November – and a new fee for every shipping container transiting the country.

Until Pakistan got its apology, the border would remain closed, forcing NATO to transit all supplies through a costly aerial route in Kyrgyzstan.

Just a day before the U.S.'s July 4 national independence holiday, the U.S. apologized, Pakistan has reopened the border, and it even dropped the shipping fee. Trucks could begin transiting as soon as Wednesday.

"I offered our sincere condolences to the families of the Pakistani soldiers who lost their lives," Secretary of State Hillary Clinton said in a statement Tuesday, following a telephone call with Pakistan's Foreign Minister, Hina Rabbani Khar. "Foreign Minister Khar and I acknowledged the mistakes that resulted in the loss of Pakistani military lives. We are sorry for the losses suffered by the Pakistani military. We are committed to working closely with Pakistan and Afghanistan to prevent this from ever happening again."

The apology, and specifically saying "sorry," was a sticking point for Pakistan. The U.S. would not go that far until today, previously issuing cautious expressions of regret and condolences. The new demand for a $5,000 fee per container was also subject to haggling. Pakistan lowered the demand to $3,000 per container, and now looks to have dropped it altogether.

"Pakistan will continue not to charge any transit fee in the larger interest of peace and security in Afghanistan and the region," Clinton said. Clinton added that the move is a "tangible demonstration of Pakistan's support for a secure, peaceful, and prosperous Afghanistan and our shared objectives in the region."

In recent days, senior U.S. and Pakistani officials have met in a "flurry," reported The New York Times. The U.S.'s top general in Afghanistan, Gen. John Allen, met last week with Pakistan army chief of staff Gen. Ashfaq Parvez Kayani in Islamabad. Deputy Secretary of State Thomas Nides visited Islamabad on Monday. And over the weekend, Clinton telephoned Pakistan's new prime minister, Raja Pervez Ashraf, and the two reportedly discussed the supply routes.

Relations haven't always been this approachable. Last November, a U.S. commando team operating at night one kilometer from the Pakistan border reportedly came under heavy and accurate machine gun fire – from a ridge in neighboring Pakistan. After supporting F-15s, Apache attack helicopters and AC-130s gunship dropped flares in a "show of force," the shooting continued. Then the helicopters and gunships opened fire. Twenty-four Pakistani soldiers were killed.

Pakistan closed the border to "Ground Lines of Communication" – or GLOCs – following the clash, and kicked the CIA out of a Pakistan-based airfield used for launching drones. NATO's supply chain was forced to rely on routes through Russia and Central Asia, which is exorbitantly costly, averaging a shipping cost of $15,800 per container. (That's significantly more than the $6,200 a Pakistan-routed container costs, even when tacking on the $5,000 fee Pakistan wanted.) In total, shifting routes back through Pakistan could save $100 million per month.

As Danger Room reported in December, the U.S.'s investigating officer, Air Force Brig. Gen. Stephen Clark, noted that the U.S.'s "reliance on incorrect mapping information" helped result in a "misunderstanding about the true location of Pakistani military units." Also problematic: the U.S. did not relay certain communications to Pakistan, due to a perception among troops that Pakistan collaborates with the Taliban.

But for now, both sides are playing nice. "Our countries should have a relationship that is enduring, strategic, and carefully defined," Clinton said, adding that such a relationship "enhances the security and prosperity of both our nations and the region."