Last week, with the announcement of modified troop plans for Afghanistan, US President Barack Obama also reiterated that there would be no shift in US strategic thinking vis-a-vis Pakistan and that Washington has no desire to change the status quo.

After the killing of Taliban leader Akhtar Muhammad Mansur in Pakistan last May, many observers erroneously concluded that the incident was a "major break" and "a telling manifestation of the change in US-Pakistan relations", one which would "provoke a crisis" in the relationship between the two countries.

However, last Wednesday, while touching upon the killing of Mansur in a US drone strike, Obama deliberately made no mention of Pakistan, where Mansur and his predecessor, Mullah Omar, both lived and died in hiding.

It was therefore strange to hear the US president calling "on all countries in the region to end safe havens for militants and terrorists", with no reference to Pakistan at all.

Long-term strategic interests

From the Afghan perspective, this means giving assent to the Pakistani military's brutal war in Afghanistan in the guise of fighting the Taliban and the Afghan insurgency.

READ MORE: Ashraf Ghani's war strategy will fail

Why does Washington tacitly embrace Pakistan's duplicity on Afghanistan?

The US has major long-term strategic interests and objectives in Afghanistan and the region (South and Central Asia) which are being facilitated and protected through Pakistan and an open-ended US military presence in Afghanistan.

According to US calculations, Pakistan must remain in the US sphere of influence. This harsh reality is why Americans look the other way when Pakistan says one thing and does another.

"When Pakistani support becomes necessary, as during the anti-Soviet jihad of the 1980s," wrote Robert Grenier, a former CIA Chief of Station for Pakistan and Afghanistan, in 88 Days To Kandahar, "America finds a way to overlook Pakistani misdeeds and focus instead on common interests. After 9/11, we found ourselves in another such cycle."

After the fall of the Taliban regime in Afghanistan, Pakistan's military rulers owned a policy of selective counterterrorism. While they detained and sold hundreds of al-Qaeda operatives to Washington, the Taliban's comeback in Afghanistan was accelerated from Pakistan, under US watch.

After the fall of the Taliban regime in Afghanistan, Pakistan's military rulers owned a policy of selective counterterrorism.

During the tenure of President Pervez Musharraf, "the ISI encouraged the resurgence by providing training, a safe haven, and even some advisers" to the Afghan Taliban and Pakistani terrorist groups to intimidate Afghanistan and challenge its stability.

The Bush administration "allowed Pervez Musharraf to give the Afghan Taliban a sanctuary", according to Bruce Riedel, a former CIA officer, a senior adviser to US presidents and author of Deadly Embrace.

After the collapse of the Taliban regime in Afghanistan, the CIA received "no policy guidance" regarding senior Taliban leaders in Pakistan.

The CIA station in Pakistan "would come across reports indicating that members of the Taliban Shura were pitching up in Quetta or Karachi", but the "leads" were then passed to the Pakistani spy agency to investigate, as claimed by Grenier.

It was "obvious", he argued, that Pakistan had no intention of chasing the Taliban on its soil.

New post-Taliban strategy

For the Pakistani intelligence agency, in this new post-Taliban strategy, low-cost Pakistani terrorist groups from North Waziristan region also became an asset - beside the Afghan groups - to run a controlled chaos in Afghanistan.

READ MORE: Afghan peace talks - Pakistan's credibility on the line

The Pakistani government denies it but to Karzai's government, senior US officials disclosed accounts of Pakistani support for the Taliban and other anti-Afghanistan groups.

In his book, After the Taliban: Nation-Building in Afghanistan, James Dobbins, the special US envoy for Afghanistan and Pakistan, wrote that Pakistan's ISI and Frontier Force "collaborated with the Taliban and other insurgent groups operating out of Pakistan's border regions".

US Army General John Campbell, the last American and ISAF commander in Afghanistan, publicly acknowledged that "based in, and operating from Pakistan HQN [the Haqqani network] remains the most virulent strain of the insurgency" in Afghanistan.

The HQN "presents one of the greatest risks to Coalition forces, and it continues to be an al-Qaeda facilitator", he added.

The Pakistani government remains in a state of denial, stating that it "condemns all forms and manifestations of terrorism" and that peace in Afghanistan is in the "interests of Pakistan".

Nevertheless, whenever questioned on the lack of action against the Pakistani dimension of the conflict in Afghanistan, senior US officials including Obama repeatedly put Karzai in the picture that "Pakistan is not susceptible to an American military response".

But addressing the problem of Pakistan's relationship with terror, does not necessarily mean taking a military action against the country.

In a telephone conversation, in 2014, while discussing preparations for the Bilateral Security Agreement between the two countries, Obama told Karzai that Washington "cannot open another front against Pakistan". Pakistan is a strategic "ally" in the war on terror.

During a visit to Washington, in 2013, Obama asked Karzai to take Pakistan's "concerns" about the Indian influence in Afghanistan "seriously".

It was a baseless Pakistani narrative coming from a US president. I would argue that if, as a matter of fact, the Pakistani Taliban (TTP) has sanctuaries in Kunar (as claimed by Islamabad), and from there they plan and carry out attacks on Pakistan, Washington should be answerable for it. As late as mid-2014, there were "more than 60" small and big US military installations in the province.

Double dealing

In the fullness of time, the Bush and Obama administrations both remained largely passive to take firm action against Pakistan's double dealing in its foreign and security policies on Afghanistan. Today, like in the past, the Pakistani military establishment serves the US in securing its strategic interests in south and central Asia.

In this risky role, as stated by a former senior US official in Grenier's account, "the unwritten rule for Pakistan has been never to admit engaging in activities of which Washington disapproves; and in fact, such duplicity is tacitly welcomed by the Americans during times".

Yet, Washington will further risk trouble with Afghanistan and regional powers. Disregarding the undeniable role of Pakistan's military and intelligence services in nurturing and harbouring Taliban and other violent groups destined to upset the stability of the region will undoubtedly lead to calamity and ruin, in all likelihood another 9/11.

Instead of prolonging the futile war in Afghanistan, the US and NATO must tackle the origins of security threats and the key problem of sanctuaries in Pakistan.

Aimal Faizi is an Afghan journalist and former spokesman for former Afghan President Hamid Karzai from 2011 to 2014.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.