As The US and NATO troops withdrawal has already begun, a vital component to prevent the Taliban not to overrun Afghanistan will be how Afghanistan’s security sector can reform to preserve the achievements. In order to implement such reform, we shall review the lessons of 2002-2003. It is true that the Afghan National Defense and Security Forces (ANDSF) have undergone deep changes and they are in a dramatically different context. However, key lessons from that period remain relevant to guide thinking what reforms the ANDAF needs to be capable to address the new security challenges of the country.
In order the ANDSF to address the new security challenges the following issues shall be considered.
1. Appointing Effective Leaders
Appointing the right leaders is vital to forging consensus on inherently divisive issues in the context of Afghanistan. These leaders must put the national interests first and shall represent all Afghans. They also must be capable and knowledgeable, and make effective use of national and international advisers and best practices. Directing and coordinating the activities of Afghan security forces is a full-time job and the ANDSF leaders shall earn and keep the trust of all ethnic groups of Afghanistan.
2. Maintaining the Capability of the ANDSF
A key task in 2002 was getting Afghans to agree on future ANDSF configuration, size, mission, and funding. After 2001 there was a very real threat the army would not be able to adapt fast enough in capability and size to stop the nation from returning to a civil war. This is a big concern today, especially if peace talks fail.
Afghanistan has witnessed a dramatic security change after the US and Taliban peace agreement. Although the Taliban had promised they will reduce the violence, target killing, attacking schools, universities, civilians and security forces doubled after the agreement. Many security analysts believe Taliban will increase violence if peace talks fail. However, Taliban have no commitment to a political settlement, they strongly believe in military victory and even Mullah Haibatullah emphasized on military takeover in his Eid ul Fitr message. Therefore, ANSDF must be large and capable enough to secure the country and suppress Taliban and other terrorist groups.
According to military experts one effective sustainment mechanism is to create a NATO-funded regional counterterrorism and Special Operations Forces training center of excellence in Afghanistan. This mechanism not only helps to unify and improve regional counterterrorism operations and special operations’ capabilities, but it can be used as a source of funding for the ANDSF as well.
3. Earning the support of Former Rivals of the Taliban
As Taliban and other terrorist groups that operate under the cover of Taliban show no commitment to the peaceful settlement, security leadership require to mobilize mujahidin groups against the Taliban and other terrorist groups. In 2002 former combatants from various rival militias were mobilized to serve in new military units together under the training and leadership of former rival civil-war commanders and even communist-era army officers. It is necessary to build patriotism inside the force, and use the force to build national pride across the country. The Afghan government shall open the space for all mujahidin groups to join the ANSDF in order to fight the Taliban and other terrorist groups that try to overrun the country and change it the safe haven of the terrorists. The only way to succeed the security forces—regardless of who is leading the country politically— is to earn the trust of the Afghan people, and practice political neutrality. However, it requires different ethnic groups have equal opportunity in the security sector.
Maybe the most critical question facing Afghan Security Forces leaders will be how to gain the trust of the Afghans to join the security forces with a sense of patriotism. Getting an early buy-in for ANDSF leadership from the different ethnic groups will be critical. As the security deterioration move forward, the ANDSF leadership discussions might seek to solicit the input of different groups of people and previous commanders on the highest priority goals for the ANDSF. Increasing trust between these groups of people and military and police might prompt the early inclusion of their previous fighters into ANSDF. 
Considering the increased violence in Afghanistan, the future ANDSF requires sustainable solutions. ANDSF leadership shall learn from the good national and international lessons of the past in terms of rebuilding the security sector in Afghanistan. At the same time, the Afghan government shall fix the major flaw of the 2002-03 process and shall successfully realign the security sector to meet a changing security situation. Sustainable international support and providing equal opportunities in the security sector to all Afghans are the key factors to ensuring a capable ANDSF that can encounter Taliban and other terrorist groups effectively.