Sunni Islamist jihadi groups have overthrown the Assad regime in Syria. The groups are led by Hayat Tahrir as-Sham (HTS), a former al-Qaeda affiliate. However, HTS leads a complex coalition of many groups and sub-groups, which formed from the milieu of jihadi groups that have been fighting in Syria since the start of the civil war in 2011.

Establishing control over the entirety of Syria will be very difficult for the country’s new rulers. Over and above the numerous jihadi groups, many ethnic and religious minorities armed themselves during the civil war to protect their villages and local autonomy (during the height of the Syrian civil war, there were over 1,500 armed groups in Syria). They will welcome the end of the dictatorship, but many, such as the Kurds, Alawites and Druze, will not welcome an imposition of Arab nationalist, Sunni Islamist rule. Further internal conflict appears probable.

Indeed, it will not be surprising if Syria reverts to full-scale civil war, which has been largely in abeyance over the last few years. If it does, it will be different to the fighting that occurred between 2011 and 2014, because the Syrian army – by far the largest and most powerful player at that time – is now likely to be removed from the equation. It will be interesting to see to whom the soldiers (and their armaments) will declare loyalty in the coming days and weeks, or whether the army will split, or simply disintegrate.

In order to understand how the situation in Syria will play out regionally, the Middle East’s strategic environment must be understood.

What is the Middle East’s strategic environment?

There are three broad groupings – the Status Quo Ante Bloc, the Resistance Bloc and the Sunni Islamist Continuum. These aren’t defined treaty organisations like NATO or ASEAN, but rather groupings defined by common interests (and common enemies), which often results in cooperative tactics.

Understanding these groupings is important because each fears and is feared by the other two. Where they overlap is where most of the region’s violent conflict occurs.

Status Quo Ante (‘as it was before’) Bloc

Primarily made up of the Sunni Arab dictatorships, they want the Middle East to return to how it was before 2003 – stable, with Iran relatively contained and the US guaranteeing regional security. Israel is a proxy member. Although most members are dictatorships (whether monarchical or military), the Status Quo Ante Bloc wants what the West wants – the free flow of oil and trade, and regional stability. It’s the bloc the West should be supporting. A key weakness of the Status Quo Ante Bloc is that many members don’t offer their people anything politically; they are corrupt dictatorships that suppress civil rights, as well as minority ethnic and religious identity.

Resistance Bloc

Led by Iran, with its proxy network made up of Hezbollah, the pro-Iran Shi’ite Iraqi militias (collectively known as the Popular Mobilisation Forces) and the Houthis. Until the weekend, Syria was a key member. The Resistance Bloc wants to replace the US with Iran as regional hegemon. It foments unrest in all countries with a substantial Shi’ite population. It conducts terrorism in the region and internationally, and is also heavily involved in international criminal networks.

Sunni Islamist Continuum

Not a bloc, but the whole spectrum of Sunni Islamist groups, ranging from the peaceful (but still extremist) Hizb ut-Tahrir and the Muslim Brotherhood to ultra-violent groups like Islamic State. HTS is definitely part of this Continuum.

(Interestingly, Hamas has long managed to skilfully straddle the Sunni Islamist Continuum and the Resistance Bloc, accepting largesse from both. Since both seek Israel’s violent destruction, Hamas fits both their agendas)

Qatar and Turkey are state members of the Continuum. Qatar is significant because it operates al-Jazeera, whose news and propaganda aim to undermine the legitimacy of the Arab dictatorships in the name of Sunni Islamism. Turkey is significant because it is a key backer of the Islamist groups that just overran Syria. Turkey is thus the big winner of the weekend’s events.

In Syria, the Sunni Islamist Continuum has overcome the Resistance Bloc. The Status Quo Ante Bloc is watching and waiting, for now.

Here are some of the possible ramifications:

• The Resistance Bloc (Iran) will find it much more difficult to rehabilitate Hezbollah.
• The Status Quo Ante Bloc, knowing that the Resistance Bloc is substantially weaker, might try to pressure the other Resistance Bloc proxies in Yemen and Iraq.
• With the Sunni Islamist Bloc on the ascendancy in the Levant, some Islamists might seek to take the fight to Israel, or seek to undermine other Status Quo Ante countries – not least neighbouring Jordan.
• Turkey and Iran measure the length of their rivalry in centuries. Turkey will likely become a significant player in Syria, having orchestrated the removal of the Iranian presence. Turkey is ostensibly a Western ally, but puts its own interests and those of Sunni Islamists ahead of those of the West.

Outside powers also play a significant role in the region. The US doesn’t want to get involved in more wars, and doesn’t have a dog in the fight in Syria, anyway. The US is an increasingly reluctant backer of the Status Quo Ante Bloc. But that support is waning with successive administrations expressing a desire to depart the region. It is unclear whether the Assad regime’s fall will strengthen or weaken Washington’s backing of regional powers.

Russia has a considerable naval base in Syria, and has long backed the Syrian regime – and in recent years has developed a strong relationship with Iran and its Resistance Bloc. However, bogged down in Ukraine, Moscow proved unwilling or unable to help its friends – and its regional credibility will now take a major hit.

China, despite pretensions, is not yet a serious player in the Middle East but might seek to increase its engagement with Iran.

What about Israel?

• There are both benefits and risks associated with the end of the Assad regime. It will significantly disrupt Iranian efforts to rehabilitate Hezbollah, and Syria was a key link in the ‘Ring of Fire’ strategy Iran had been trying to build around the Jewish state.
• However, Sunni jihadis on Israel’s border and/or a vacuum filled by warring jihadi, ethnic and religious militias also presents a potentially serious threat. Having ‘an address’ to respond to is a key requirement for a deterrent effect to be established. Syria, under Assad, had long been militarily deterred by Israel. Now it looks likely there will be no such ‘address’, leaving Israel’s previously quiet border with Syria considerably more dangerous. Israel has moved its troops to (and, in places, slightly beyond) the Israel–Syria border. For 50 years, there has been a demilitarised zone at the border; with the fall of the Syrian regime, Israel has declared the arrangement null and void. Israel has also reportedly launched strikes on non-conventional weapons sites in Syria, such as chemical weapons manufacture and storage facilities, so as to prevent them from falling into jihadi hands.
• If the new forces dominating Syria threaten Jordan, Israel will likely help shore up Amman. In 1970, Israel prevented Syrian forces invading Jordan in support of Palestinian militias fighting to overthrow the Hashemite monarchy. Jordanian stability is regarded as a vital national interest by virtually all Israeli military and political analysts.