THE GHQ-Pentagon blow up last week was ugly. Admittedly, one had the feeling for a while that there was enough discontent in both military establishments that something would give sooner or later. But the bluntness of it has surprised us all.

The much-publicised US official statements about the ISI-Haqqani network connection and Gen Kayani's rather harsh rebuttal marks a new low in the bilateral partnership. The GHQ and the Pentagon have had a truly 'special' relationship going all the way back to the 1950s. Even in the post-9/11 context, both military establishments have viewed each other as their most ardent defenders. And there is a fair bit of truth to this. tactical

In Washington, DC, where Pakistan is not exactly the most liked country, it was the Pentagon that was most understanding and patient with Pakistan. Over in Pakistan too, the military high command constantly worked with the American counterparts behind closed doors to fulfil their demands. This is not to say that there were no differences, or more accurately put, that tensions were not frequent. But despite hiccups, ultimately, a bird's eye view of the last decade would show that the two militaries have had tremendous cooperation at the level.

Two obvious questions arise: why was the blow-up out in the open? And does this imply a rupture of the military-military relationship?

The obvious way to answer the first question is to recount the events since the Raymond Davis affair and how the positions of the two sides have diverged on specific issues such as presence of CIA operatives in Pakistan, use of drones, etc. Indeed, these were the proximate causes for what we heard last week. The timing of the blow-up is also explained by these events. But the real underlying tensions, which ultimately have prompted a public display of anger and an implicit threat of more to come, are attributable to something deeper, something more troubling, about how the two militaries are viewing the present situation unfold in Afghanistan. The virtually irreconcilable strategic difference on Afghanistan lies at the heart of the heated exchange.

The military-military relationship over the past decade has been schizophrenic. Even as the tactical cooperation grew, the structural strategic divergence on what end-state the two sides were looking for in Afghanistan was never resolved. And thus, both parties while cooperating tactically, operated on their own tangents strategically.

Why did they keep this formulation going?

Essentially because tactical cooperation was necessary for the US, and Pakistan was being reimbursed handsomely; and strategically, both sides hoped that they would ultimately be able to convince the other of their position and woo them to their side. Washington hoped Pakistan would give up sanctuaries; Pakistan thought US would dump a military-driven option, initiate talks with the Taliban much earlier and address Pakistani concerns vis-à-vis India.

No longer can this hold. For one simple reason: the 2014 timeline for Afghanistan's 'end-game' is approaching fast enough that both sides need action from the other, and need it now. The US wants Pakistan to do something about the sanctuaries, without which it cannot succeed in Afghanistan; in fact, even for a 'narrative of victory' to be credible, it needs Pakistan to oblige. including the three insurgent groups with sanctuaries in Pakistan

Among Pakistani thinkers on the other hand, there is a growing sense that if the present US strategy continues any longer, it will be detrimental to Pakistani interests. Forget any support for targeting sanctuaries — the view in Pakistan is that US strategy needs an immediate rethink away from military action. The preferred option is for reconciliation talks to begin immediately and for a negotiated settlement acceptable to Afghans, .

There is then, perhaps for the first time, a realisation on both sides that their hope of prompting a strategic rethink (on the other side) has all but failed. They have run out of time. And thus, they are clutching at straws. Both are trying to up the ante; play diplomatic brinkmanship; raise the stakes to the point that the other buckles; convey that the time for niceties is over.

And how do you do that? By using any and every opportunity to arm twist; by taking certain unilateral actions you know the other side will not like; by public shaming; by signalling that even the most trusted partners on the other side (militaries in this case) can wait no more; by beginning to leak evidence to help your case. Since the failure of the 'behind-closed-doors' approach has led them to this point, they will now want to conduct much of this brinkmanship publicly. And thus, it is bound to be ugly.

So does this mean that the relationship is headed towards a rupture?

Interestingly enough, the answer is no. For the same reason that has held the two sides together for the past decade, i.e. they cannot do without each other. Neither can the US survive without Pakistan's tactical cooperation and the supply routes it provides, nor will Pakistan be able to withstand the economic repercussions and the isolatory effects of an outright antagonistic relationship with the US.

The above said, an inherent danger in this kind of brinkmanship must be admitted. Repeated bouts of public anger inevitably end up providing much greater space to vested interests who would like to see an end to this relationship. If they can spin an appealing narrative and rehearse it frequently enough, they can often begin to impact even serious minds. And at some point, even state officials managing the relationship may start believing that they will be better off without their partner.

Luckily, we have not gotten that far yet. For now, one can anticipate an easing of tensions over the next few weeks, only to return in the next ugly bout. I expect this to be the norm between now and 2014.

The writer is South Asia adviser at the US Institute of Peace, Washington, DC.