Pakistan's recent release of Mullah Abdul Ghani Baradar, the Afghan Taliban's second in command, in an effort to catalyze a peace process between the Afghan government and the Taliban has not brought an end - or even pause - to the Taliban's violent attacks on Afghans, Americans, or friends and allies.

During my tenure as the US Special Representative for Afghanistan and Pakistan from 2011 to 2012, we often found ourselves reacting to Taliban actions which, in their frequency and brutality, called into question the Taliban's commitment to creating a peace process, especially the September 2011 murder of then chairman of the Afghan High Peace Council, Burhanuddin Rabbani, by a suicide bomber posing as Taliban negotiator who had come to "discuss peace."

Attacks like these prompt many to ask: Why bother talking to the Taliban? The answer is that, as both President Barack Obama and former Secretary of State Hillary Clinton made clear while I served as special representative, the war in Afghanistan is going to end politically and we would either shape that end or be shaped by it. If there is ever to be peace in Afghanistan, Afghans will need to talk to other Afghans about the future. Since the Taliban today officially refuse to talk to Kabul's representatives, getting to these talks might require a US effort to help open the door.

In February 2011, we were presented with an opportunity to do just that. An allied government had put the US in contact with someone who appeared to be an empowered representative of the Taliban. The contact, while preliminary, offered the intriguing possibility of a direct conversation - a conversation which, we hoped, could create the context for the Afghan government and the Taliban to talk.

Those US-Taliban talks, which lasted from mid-2011 to March 2012, ultimately failed. While many details rightly remain classified, here are three of the lessons I learned sitting across the negotiating table that may be helpful to those who may seek to reopen the dialogue with them or others who need to talk to an insurgent group in some present or future conflict:

Set clear conditions and moral guidelines and stick to them. These need not be preconditions. Indeed, before talks with the Taliban began, Secretary Clinton made clear that while the US had no preconditions for talking to them, Washington would support reconciliation with only those insurgents who met three important end conditions: Break with al Qaeda, end violence, and live inside an Afghan Constitution that guarantees the rights of all individuals, especially women.

The talks with the Taliban were designed to create a series of confidence-building measures consistent with these principles and designed to open the door. The measures included a requirement that the Taliban make a public statement distancing themselves from international terrorism and accepting the need for an Afghan political process. They also included the opening of a Taliban political office in Doha, which we made clear could not represent the headquarters of an alternative Afghan government, be an insurgent recruiting station or a venue of raising money to support the insurgency. They also involved the possible transfer of Taliban prisoners from Guantanamo and the release of US Army Sergeant Bowe Bergdahl, who has been held by the Taliban since 2009.

Ultimately, we did not reach agreement on any part of this sequence. Still, the moral ambiguity of talking to insurgents was clarified by our commitment to the principles Secretary Clinton had laid out before we started to talk.

It is hard to fight and negotiate at the same time. When the Taliban cut off the discussions, many on our team assessed that they were having a hard time motivating their fighters while talks were taking place. And while we met with a representative of the Taliban Political Commission who seemed interested in a negotiated end to the conflict, the Taliban Military Commission appeared to want to continue the fight - and did so in an unconstrained manner, using brutal tactics such as attacks on schools and hospitals, and the assassination of Rabbani.

Talking and fighting simultaneously were also challenges in our own government. We consistently reexamined the possibility that the Taliban had entered into the conversation to keep us busy or distracted while they continued to carry out military operations, waiting for our ultimate withdrawal.

Force must be backed by diplomacy, and diplomacy must be backed by force. Talking with the Taliban was part of the larger "diplomatic campaign" Secretary Clinton launched in 2011 to complement the military surge President Obama had ordered in 2009. This diplomatic campaign tried to harness all of the instruments of non-military power to support Afghanistan, such as development assistance, private-sector investment and support for civil society.

As part of this effort, we organized international meetings in Istanbul, Bonn, Chicago and Tokyo, at which nations and international organizations pledged future political and material support for Afghanistan. These conferences were also designed to send the Taliban clear messages that the international community was committed to supporting Afghanistan beyond 2014.

A peaceful end to the war now requires that the international community meet the commitments it has made to Afghanistan. President Obama also faces the challenging question of how many US troops to leave in Afghanistan after December 2014 to support the Afghan National Security Forces and fight terrorism. A robust number would be an essential signal to Afghans and would promote contributions from other allies and partners. The Taliban will be astute judges of whether Afghans have the will to fight and whether we have the will to support them.

It may be that the talks we launched in 2011 were premature and that direct talks among Afghans about their future may not be possible until after the Afghan presidential elections and the transition of the NATO mission in 2014. Still the effort was worth it - and remains so today. Perhaps the release of Mullah Baradar will spark some new thinking among the Afghan combatants. They might contemplate the words of former Irish Prime Minister Bertie Ahern, who said of the great challenges of negotiating with the Irish Republican Army, that while he could not stop the killing of the last decade he might stop the killing for the next one. "The reward," Ahern said, "is there aren't so many funerals."

(Marc Grossman is a vice chairman of The Cohen Group and a Kissinger Senior Fellow at Yale's Johnson Center for the Study of American Diplomacy. A Foreign Service Officer for 29 years, he retired in 2005 as Under Secretary for Political Affairs. He was recalled to service as the US Special Representative for Afghanistan and Pakistan 2011-2012. This article is drawn from an analysis of lessons learned from talking to the Taliban that will appear later this year in Prism, published by the National Defense University and from a review of the diplomatic campaign in Afghanistan and Pakistan in the Yale Journal of International Affairs, Summer 2013. The opinions and characterizations in this article are those of the author and do not necessarily represent the official positions of the US Government. This is reprinted with permission from the Yale Center for the Study of Globalization)