The signing of an agreement between the United States and Pakistan on Tuesday on Nato supplies through Pakistan to Afghanistan marks a breakthrough in the relations between the two countries.

Islamabad-Washington relations have been sinking to new lows in the past few months, one of the reasons for which was Pakistan’s blockade of Nato supplies to Afghanistan. With the new deal, the seven-month blockade comes to an end and though this development can’t be expected to restore relations to their heydays, it removes a major irritant and can pave the way for wider cooperation after months of acrimony.

According to reports, the deal in essence formalises the existing practices by putting them in black and white. Pakistan will allow supply convoys to cross its territory into Afghanistan until the end of 2015, one year beyond the deadline for withdrawal of US forces there. It also formalises some key details, including a ban on transporting lethal equipment, and says that Pakistan will provide security for the thousands of container trucks and oil tankers whose routes originate at the port of Karachi.

Pakistan police stationed in cities and towns will handle security until the convoys reach the tribal areas bordering Afghanistan, where Afghanistan’s paramilitary Frontier Corps will take over. All containers will be scanned twice, at the port of entry and the port of exit, to ensure they don’t contain lethal equipment. However, shipments of some categories of weapons may be allowed on the way back from Afghanistan.

Another significant feature of the deal is said to be that it was reached without an open involvement by Pakistan’s military. This time, the generals stood back to allow civilian leaders to negotiate the deal.

Pakistani officials have described the route agreement as a watershed moment, saying that the “one phone call” days of relations between the two are over and a sign that civilian rulers have a voice in foreign policy.

Pakistan and US are two allies who need each other, though a few on either side might differ. As the US plans the withdrawal of its troops from Afghanistan, it needs Islamabad’s help to complete the exercise.

For Islamabad, the immediate benefit of the deal is that it paves the way for the release of $ 1.18bn in Coalition Support Fund reimbursements held up for over two years.

Both sides now need to address the contentious issues that spoil their relations. Washington is accusing Pakistan of supporting terrorists on its soil, which Islamabad denies, while the latter has accused the former of committing excesses in the war on terror. Success on this front is tougher than expected and both sides are aware of the pitfalls ahead.

It’s a rollercoaster ride, but ultimately better sense and diplomacy will prevail.