The civil war in Yemen, exacerbated by the intervention of outside powers, is poised at a delicate stage which could impinge on the larger picture of the Middle East’s future trajectory. The truth is that the poorest country in the region lies along several fault lines.

They are the Shia-Sunni schism in the Muslim world, the rivalry between Saudi Arabia and Iran, the interest of outside powers such as the United States and the major European trading nations and the broader state of US-Russian relations. Despite its appeals, the United Nations is, for the present, a spectator, rather than an effective actor.

The military intervention of Saudi Arabia and its Gulf allies by launching air strikes on Houthi rebels in Yemen, who are aided by Iran and are in the process of capturing the better part of the country, has complicated the picture. In a sense, it was inevitable because Riyadh could hardly stand aside even as a Shia sect set about conquering a Sunni majority country. The Saudis are now demanding the surrender of the Houthis before stopping their bombing runs.

The United States is helping the Saudis by providing logistical and other technical assistance, a delicate dance for US Secretary of State John Kerry. He decries Iranian help to the Houthis. Tehran denies even as he eyes a landmark deal with Iran on its nuclear program. Pakistan, on its part, is facing a cruel dilemma in accepting the Saudi demand to join the intervention against the backdrop of its substantial Shia population at home.

For Pakistan, the dilemma is of a state beholden to Riyadh for its generous subsidies. A contingent of Pakistani troops is permanently stationed in Saudi Arabia in part payment for Saudi goodies. Prime Minister Nawaz Sharif himself is beholden to the Saudis for saving him from possible execution in the days of Gen Pervez Musharraf rule, first giving him refuge and then re-injecting him into the Pakistani political scene.

Grave as the dilemmas for Pakistan are, the larger picture is more menacing because of the fault lines. The most salient is the Saudi-Iranian contest in the Middle East in which Tehran is seeking to spread its wings through fortuitous circumstances and its own activism. Thanks to the American invasion of Iraq, the latter, with its Shia majority, ultimately fell into its lap. Iran is well placed in Lebanon with its allied Hezbollah movement in a confessional division of political factions.

Bahrain remains a tempting target because it is ruled by a Sunni monarch underpinned by Saudi power over a Shia majority. Saudi apprehension over the proposed nuclear deal with Iran, shared by Israel, is that it would give Tehran greater opportunities to strengthen its regional role.

As if the picture were not complicated enough, the growth of Sunni extremists, first in the form of Al-Qaida and its affiliates, then their evolution into ISIS and ultimately into a caliphate holding territory in the shape of the Islamic State (IS), is a fact of life. Americans have reluctantly returned to the region by undertaking bombing runs on the IS and are ironically on the same side as Iran in trying to attain this goal.

How then is the world, or the major powers, to unscramble the mess because of the very nature of the crises? If relations between the United States and Russia were not as frigid as they are over Ukraine and other issues, they could have joined hands to bring about at least a temporary ceasefire in Yemen. After all, in the five plus one (UN Security Council permanent members plus Germany) format of talks on Iran’s nuclear program, Russia was a participant. But the prevailing animosities in what was once the Big Two make the going tough.

Individuals and circumstances have contributed to creating the Yemen crisis. Mr. Ali Abdullah Saleh, the long-time dictator, was eased out of office with the help of Gulf monarchies in the wake of the short-lived Arab Spring in 2011. He was nursing his wounds while keeping his powder dry and still had ambitions – for son, if not for himself. He chose to ally with the Houthis while still retaining the loyalty of sections of the country’s armed forces.

Houthis, who traditionally control the north of the country, were ready to revolt against the Sanaa dispensation presided over by an unimpressive Sunni imposed by Saudis. They felt their interests were being sacrificed and, thanks to Saleh’s support, they had the strength to overrun the capital and even try to take over Aden, the principal city of South Sudan.

The nature of the strikes being what it is, there are reports of increasing civilian casualties. Although some humanitarian aid has now got in and India, among other countries, has managed to evacuate most of its citizens, international demands are growing by the day to stop the bombing runs and seek a political solution.

Houthis, being a minority, cannot hope to rule Yemen. Yet, given the military prowess they have demonstrated, they will insist on a fair share of the national cake in any future framework agreement. Saudi Arabia shares a long border with Yemen and will not tolerate a Shia-dominated dispensation despite the earlier long rule of Mr. Saleh, himself a Houthi.

For its part, Iran has already suggested that the Saudi-led action is a “mistake” and the United States is seeking to maintain a balance between the hoped-for nuclear deal with Iran and warnings to Tehran to refrain from aiding the Houthis. Ultimately, the problem will land in the lap of the United Nations, but the question is how much longer the process will take and how long the regional contestants will drag their feet before a truce is called.

The scale of the fighting and deaths is leading to growing demands for a ceasefire. The Saudis have made their point that there cannot be a Shia-dominated dispensation along its shared border. But a compromise must include a fair sharing of power with Houthis.