Yemeni troops are now in control of the town of Jaar after weeks of a massive military push to dislodge al-Qaeda from southern Yemen.

In March last year, Ansar Sharia, an al-Qaeda-linked group, swept into the city and established an "Islamic Emirate".

Taking advantage of chaos in Yemen and a prolonged political crisis that weakened the government and divided the army, al-Qaeda expanded its reach in southern provinces.

Hundreds of Arab and Asian fighters crossed into the country and blended with the local population.

After some time they established governing bodies, including a judiciary system based on Sharia, Islamic law, that launched an anti-corruption campaign and set up a morality police to promote virtue and crackdown on vice.

It was an attempt to win the hearts and minds of an impoverished population disillusioned with the political establishment.

When Yemen's former president Ali Abdullah Saleh was busy clamping down on protesters calling for political reforms, Ansar Sharia were launching daring attacks against army units in Shabwa and Abyan governorates, seizing weapons and ammunition.

Responding to US pressure to take tougher action, the government launched a major operation in Abyan to regain control of Jaar and Zinjibar. Backed by thousands of tribal fighters and US drones, the army cordoned off the whole area and pounded al-Qaeda’s positions.

Ansar Sharia fighters rejected repeated calls for surrender, arguing their fight is legitimate and a religious duty against a “corrupt government” backed by “infidels” - a term they use to describe the Americans.

The fall of Jaar and Zinjibar is a significant victory for the army, but does not necessarily amount to the final defeat of al-Qaeda. Hundreds of its fighters pulled out to safer areas like Shuqra, and to the Shabwa governorate where they enjoy the protection of tribal leaders.

In 2009, a video posted online showed three men - Naser al-Wuhayshi, Qassim al-Raimi and Said al-Shihri - announcing the forming of al-Qaeda in the Arabian Peninsula (AQAP). Two years later, it became known as al-Qaeda’s most active affiliate.

Weeks later, investigations into a failed attempt by a Nigerian to detonate explosives sewn to his underwear while onboard a US bound flight, revealed the man was trained by al-Qaeda in Yemen.

Al-Qaeda’s activities were already under the radar of the US administration which stepped up drone attacks to get rid of the group’s leaders. In September 2011, the charismatic cleric and spiritual leader of AQAP Anwar al-Awlaki was killed along with his aide Samir Khan, editor of AQAP’s English language magazine Inspire. Both men were US citizens.

The fight against al-Qaeda in Yemen will likely continue for some time. But for the new government to garner popular support for its military campaign, it has to restore stability, push the transition process forward and reform the army. If the political factions remain divided on who should lead the post-Saleh era, al-Qaeda will always find a way to stage a comeback.