I have been covering Yemen for many years and each time I am intrigued by its opaque political system, complex social fabric, ever shifting loyalties and growing influence of the Shia Houthis aka Ansar Allah [Partisans of God].

The latest spate of violence in the capital Sanaa and the ongoing political impasse stand as a reminder that the country could disintegrate if its political leaders fail to agree on a roadmap for the remainder of the transitional period.

And this is the crux of the matter; Yemenis are so divided that they may never be able to strike a deal without regional and international support.

But Yemen has slipped off the radar screen of the world for quite some time. Those who show interest do so obviously for a reason.

They want to defend their political interests. But now unless there is a coordinated effort to solve the crisis, violence may spin out of control.

In a dramatic turn of events, Yemen's President Abd-Rabbu Mansour Hadi and the government resigned last week.

In his resignation letter Hadi said he could not stay in office anymore with the Houthis challenging his authority.

Hadi’s reputation was in fact put on the line when Ansar Allah swept through the capital last year, controlling an area that stretches from Saada, their power base on the border with Saudi Arabia north, to the province of Thamar, south of the capital.

The Houthis established militias with sweeping powers. They can storm a ministry and arrest officials on suspicions of corruption. 

The popular committees  are widely seen as a state within the state. But for the Shia group, those fighters are crucial to maintain stability in a country where security forces have been weakened by decades of instability.

Hadi and his loyalists say this is just an excuse to topple the government.

Is President Hadi still in charge?

In theory it is President Hadi who runs the country. He has an army, a police force , and a government implementing his vision for Yemen.

But his authority was dented beyond repair on 21 september 2014 when the Houthis took over the capital.

Hadi is now confined to his residence, his orders largely neglected. This is an ultimate act of humiliation for the former general. Millions pinned hopes on him when he was elected president in 2012.

He was then portrayed as a savior. Now the saviour needs someone to come to his rescue.

President Hadi is originally from the southern province Abyan, where the predominantly active Sunni secessionist movement is calling for the south to break away from the north.

If evicted by the Houthis, the Sunni majority may take up arms. This is why the Houthis have refrained [for the time being at least] from talking about Hadi’s departure.

Hadi’s resignation could be a tactical move to force the Houthis into making significant concessions, particularly when it comes to pulling their fighters out of the capital.

But his decision could backfire if the Houthis stand their ground.

Also if he changes his mind and stays president without regaining full authority will be a fatal blow for him.

Abdel-Malik al-Houthi

Young and charismatic, he is more than a hero for the Houthis. He is a Sayyid - a  descendant of Prophet Muhammad.

By Shia standards, this credential allows him to lead his own people.

Abdel-Malik succeeded his brother Hussein who was killed in 2004. Malik has managed to build a formidable military and political movement that is now Yemen's most powerful organisation.

Opponents say the Houthis' rise to power wouldn’t have been possible had it not been for a massive military and financial support from Iran.

The government has on many occasions displayed weapons shipments it said were coming from Tehran.

Last year, neighbouring Saudi Arabia declared the Houthis a terrorist organisation.

The Saudis blame the Houthis for being Iran’s proxy in a predominantly Sunni region.

Abdul Malik Al Houthi faces tough choices ahead. To consolidate his grip on power he needs to control the province of Maarib where most of the country's oil and gas installations are located.

But that's a mainly Sunni area, representing another sectarian fault line in a country on the verge of collapse.

Ali Abdullah Saleh

The former president was overthrown in a mass protest movement in 2012. He says he was forced out of power by a coalition of Islamists and tribal leaders backed by terrorists.

But the man who ruled Yemen for 33 years wields huge influence in the country.

He still has the loyalty of powerful tribesmen, military commanders and businessmen. Elite units at the army still take orders only from him.

The man who once said that ruling Yemen is like "dancing on the heads of snakes" is now under the spot light again.

A leaked telephone conversation obtained by Al Jazeera shows Saleh colluding with the Houthis to undermine his successor.

This could be shocking news to some people in Yemen who believe Saleh is staunchly anti Houthi. But Saleh is a shrewd tactician with a long history of brinkmanship.

He may not be willing this time to stage a political comeback but he has been grooming his son, General Ahmed Saleh, for years to become Yemen's most powerful person.

If the Houthis are the most popular Shia group, Islah is widely seen as the voice of the Sunnis in Yemen. Formed in 1990, its an umbrella  organisation of conservative and tribal movements.

The Islah was active in Shia areas until the Houthis took over most of the north. But they remain largely popular in the south and the east.

Relations between the Islah and the Houthis are strained because of the growing sectarian divide. Some of Islah's offices were recently ransacked by Houthi fighters.

Islah has also the backing of powerful militias across the country, an asset that increases its chances to remain a key player in Yemen’s politics.

Southern Movement

They are mostly disgruntled with the north. They had a state of their own until 1990 when they joined the north and formed a united Yemen.

It is a move they regret now.

They say it was a huge mistake. Unity was meant be part of a power sharing deal. But that deal was never implemented.

In their almost daily protests, they accuse the government of looting their natural resources.

After the Houthis took control of Sanaa, the secessionist stepped up their campaign for independence. They are now more determined than ever to have their own state.

Al-Qaeda in the Arabian Peninsula (AQAP) is the most active al-Qaeda offshoot in the world.

It has recently claimed responsibility for the attacks on the French satirical magazine Charlie HebdoAQAP was also behind the botched attack to destroy a plane over Detroit in 2009.

A year later they placed explosive parcels on two cargo planes destined for the US city of Chicago.

AQAP remains powerful despite ongoing US drone strikes. The group is mainly based in the two provinces of Abyan and Shabwa where it has forged ties with Sunni tribesmen.

Recently reports emerged that its fighters are moving north to confront the Houthis.

It is against the background of this convoluted political landscape that Yemen's security situation  will remain fragile.

Its continued internal feuding can trigger a war, with ramifications that may never be contained in the near future.