Jane Ferguson writes for Al Jazeera English:
All around the country, the challenges to Yemen's new government's authority are numerous --- and serious.
Yemen's new president, Abd Rabbu Mansour Hadi, was sworn into office this February after being the consensus candidate in a national referendum. He is meant to be overseeing a transition to full democracy in the country following a revolution that erupted in January 2011.
That revolution, however, spurred a violent power struggle between loyalists of the old regime --- the family of Ali Abdullah Saleh, who ruled for over 30 years - and defected factions of the military and tribes opposed to him.
As fighting broke out across the capital city, Sanaa, in 2011, various rebel groups throughout the country that had long been fighting the government, took advantage of the chaos to sweep across new swathes of territory.
One such group is the Houthis, a Zaydi Shia ethnic group in Yemen's North, based in a mountainous region bordering Saudi Arabia. Its armed fighters have been in a tit-for-tat conflict with the Yemeni army since 2004. During last year's chaos, they pushed further south towards capital, Sanaa.
They say they are seeking more autonomy and redress for what they see as neglect and discrimination.
As far back as 2009, their armed offensive was clearly becoming a regional issue as Saudi Arabia's military began engaging the group. The Houthis accused Saudi jets of entering Yemeni airspace, something the Saudis deny. And the Saudis accused Houthis of killing their soldiers along the border.
Hadi himself, when he was vice-president of Yemen under Saleh in 2009, accused the Iranians of funding the Houthis. "They are helping them," he said on a visit to a refugee camp in the North in December 2009, "by money". Experts view this small, largely hidden conflict as a proxy war between Saudi Arabia and Iran.
The Yemeni army's fight against the Houthis over the past year and a half has been one of containment. The military is split on several fronts and is not currently able to end the conflict outright.
One of those main fronts is in the south, against al-Qaeda-linked fighters. Since 2008, al-Qaeda's Yemeni franchise, al-Qaeda in the Arabian Peninsula (AQAP), has been growing in numbers and activity levels. Experts pointed to the successes of drone strikes and offensives against al-Qaeda in Afghanistan, Pakistan and Iraq, which caused many to flee to the relative safety of Yemen's more lawless rural areas in the south and southeast. Yemen is also the ancestral home of Osama bin Laden.
Bombings in the capital by the group have increased in intensity in recent years, from an attack on the US embassy in 2008 to the suicide bomber who killed more than 120 people last month. Over the past year and a half of political fighting, Ansar al-Sharia, a local al-Qaeda-affiliated group, grabbed swathes of the south, including Abyan province and various towns including its capital, Zinjibar. They have been linked closely to AQAP and are believed to work directly with al-Qaeda fighters, both Yemeni and foreign, in southern provinces.
The Yemeni army is now trying to re-take control of such areas and launched a major offensive since March. That launch coincided with Hadi's taking official power, as he vowed to crush violent extremist elements. He is helped by the US, and drone strikes in the area have increased in regularity since March. In April, the Washington Postreported that the US President Barack Obama had gained approval from Congress to launch "signature strikes" against suspected militant leaders - which effectively remove the need to confirm whom the target of such strikes are, and target individuals based on suspicion alone.
US military advisers from Joint Special Operations Command and the CIA are present on the ground in Yemen and are helping the Yemeni Army in its current offensive. The move is seen by some to be controversial, and possibly dangerous to the broader "hearts and minds" campaign the Yemeni government is waging in the south. After last month's suicide attack, which largely targeted soldiers at a military parade rehersal, al-Qaeda announced that they were taking revenge for the army's war against them and its co-operation with the US military. Following the attack, a statement released by the White House said Obama's top counterterrorism adviser, John Brennan, spoke to Yemeni President Hadi. "Mr Brennan and President Hadi reaffirmed the unshakeable partnership between Yemen and the United States," the statement read.
Local Popular Resistance Committees, made up of tribal militia fighters from various southern regions, are also fighting al-Qaeda in the current offensive. They have been attributed with successes against the group, using their local knowledge and warfare tactics. Not much is known about these groups, as most announcements on the war are made by Yemeni authorites. Some of the groups may be made up of southern seccessionist fighters, who, although seeking independence from the northern government, are also opposed to al-Qaeda.
As a result, it is unclear who is in charge of certain southern areas, and how the outcome of the fighting in these areas will affect the future of the Yemeni government.