What just happened in Yemen?

Yemen, the poorest country in the Middle East, has been in a state of political crisis since 2011 when a series of street protests began against poverty, unemployment, corruption. In recent months, though, Yemen has been driven even further into instability by conflicts between several different groups, pushing the country “to the edge of civil war,” according to the UN’s special adviser.

Yesterday, to prevent further instability, a coalition led by Saudi Arabia launched air strikes against Shia Houthi rebels in Yemen, saying it is “defending the legitimate government” of US-backed president Abdrabbuh Mansour Hadi. There are conflicting reports about whether Hadi has fled Yemen or who is in control of the government.

Egyptian military and security officials told The Associated Press that the military intervention will go further, with a ground assault into Yemen by Egyptian, Saudi and other forces, planned once airstrikes have weakened the capabilities of the rebels.

Why did Saudi Arabia get involved?

Saudi Arabia (comprised of mostly Sunni Muslims) and Iran (comprised mostly of Shi’a Muslims) are in a sort of “Cold War” conflict and in petition for influence in the region. Saudi Arabia considers the Houthis are an Iranian proxy and believe they need to take action to prevent an Iranian client state from developing on their southern border.

Do Sunnis and Shi’ite have the same beliefs mon?

Mostly, at least on the basics. For Christians, the Nicene creed is often viewed as the basic statement of faith, the essentials agreed upon by all orthodox believers. Muslims have a similar creed (shahadah) roughly translated as, “There is no god but Allah, Muhammad is the Messenger of Allah.” The Shi’ite, however, tack on an additional sentence: “Ali is the Friend of Allah. The Successor of the Messenger of Allah And his first Caliph.”

Around 85 percent of the world’s Muslims are Sunni while only about 15 percent are Shi’a. Iran is predominantly Shi’awhile Saudi Arabia, and almost all other Arab countries, are mostly Sunni.

Who are the major players in the conflict?

Forces loyal to the Houthis — Houthis are a Zaidi Shia group operating in Yemen. They are believed to be backed by Iran, though they don’t necessarily take orders from that country. Their cause is both religious and political.

Forces loyal to the Hadi government — Yemen’s security forces have split loyalties, with some units backing Hadi, and others the Houthis and Hadi’s predecessor Ali Abdullah Saleh. Included in this group is the coalition of nations led by Saudi Arabia.

Al-Qaeda in the Arabian Peninsula (AQAP) — AQAP opposes both the Houthis and the Hadi government.

Islamic State (IS) —IS views itself as the rightful leader of Muslims everywhere and as mandated by God to rule over all territories once under Muslim control and beyond, IS must spread. IS opposes everyone in the area.

Where is Yemen?

Yemen is bordered by Saudi Arabia to the north, Oman to the east, the Gulf of Aden and Arabian Sea to the south, and the Red Sea to the west.

Why should Americans care?

Oil and terrorism are the two main reasons the U.S. is concerned about the conflict.

According to the BBC, Western intelligence agencies consider AQAP the most dangerous branch of al-Qaeda because of its technical expertise and global reach. The U.S. has been carrying out operations, including drone strikes, against AQAP in Yemen with President Hadi’s co-operation, but the Houthis’ advance has meant the U.S. campaign has been scaled back. Last week 125 U.S. Special Operations advisors had to leave the country.

AQAP in Yemen have been linked to at least three plots to blow up airliners since 2009.Without intelligence and counter-terrorism forces in the country, AQAP may be able to plan operations unhindered.

Yemen also controls one of the world’s crucial oil chokepoints. According to the US Energy Information Administration’s (EIA) fact-sheet on global oil chokepoints, 3.8 million barrels of oil and “refined petroleum products” passed through the Bab el-Mandeb, the straights at the opening of the Red Sea, each day on its way to Europe, Asia, and the U.S., making it the world’s 4th-busiest chokepoint. If that straight is closed, it could limit oil supplies from Egypt, Sudan, and Saudi Arabia and cause oil prices to rise.