In the early hours of April 7, the U.S. military launched a series of missile strikes against an air base in northern Syria, in retaliation for the Syrian regime’s chemical weapons attack against civilians three days earlier.

A man breathes through an oxygen mask, after what rescue workers described as a suspected gas attack in the town of Khan Sheikhoun in rebel-held Idlib, Syria April 4, 2017. REUTERS/Ammar Abdullah

The strike shows that President Donald Trump is more willing to use military force in Syria than his predecessor, Barack Obama. But it raises another crucial question: Why would Syrian President Bashar al-Assad, whose regime has consolidated control over Syria’s largest cities in the past year and put the rebels on the defensive, risk a new international backlash by using chemical weapons? If he’s winning, why would Assad take such a risk?

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The answer lies in Assad’s refusal to compromise or offer any significant concessions since the Syrian uprising began in March 2011, and later morphed into a civil war. Assad overplayed his hand this time, after being emboldened by recent statements from White House officials that it was time for Western powers to accept the “political reality” of Assad’s continued dominance. Assad likely decided to test those boundaries, not expecting Trump to respond militarily because the U.S. president has made it clear that he sees fighting Islamic State as his highest priority in Syria and Iraq.

Aside from his brutality – the war has killed more than 500,000 people and displaced nearly half of Syria’s population – Assad’s staying power is rooted in a convoluted foreign policy, pioneered by his father, Hafez al-Assad. Syria played the role of a regional broker and Arab nationalist standard-bearer since 1970, when the elder Assad seized power through a military coup. He perfected the art of creating defensive alliances, nurturing proxies in neighboring countries and keeping his enemies stalled in costly battles.

Since he rose to power after his father’s death in June 2000, the younger Assad learned to keep all of his options open, and to play Syria’s friends and enemies off one another. Assad has portrayed himself as the only one capable of keeping Syria’s army and other state institutions from disintegrating, and preventing the country from falling entirely into the grip of Islamic extremists. To the West, Assad projected himself as the lesser evil – compared to Islamic State, and other jihadists affiliated with al Qaeda – even if his regime has instigated more death and destruction than his enemies.

Assad seems determined to replicate the foreign policy of his past, when he was able to hold on to power by being brutal, focusing outward and waiting for regional dynamics to change in his favor. To endure the pressure and international isolation imposed by the George W. Bush administration after its invasion of Iraq in 2003, Assad relied on his father’s foreign policy. The younger Assad feared that Syria was vulnerable to an American invasion, so his regime facilitated the recruiting, training and safe passage for hundreds of Syrian and foreign volunteers to join al Qaeda in Iraq to fight U.S. troops and destabilize the Iraqi government.

When popular protests first swept the Arab world in early 2011, Assad was confident that he had nothing to fear because he continued his father’s foreign policy legacy – he did not depend on American military and political support like the leaders of Tunisia, Egypt, Bahrain and Yemen.

Instead, Assad and his allies formed the “axis of resistance” – Iran, Syria and the Islamist militant groups Hezbollah and Hamas. They boasted that the revolts had proven that they are the true representative of the majority of people in the Arab and Muslim worlds, who for decades had been stifled under regimes that “sold out” to the United States.

In refusing to make substantial concessions, Assad has relied on another tactic he learned from his father: The Syrian regime does not make compromises under pressure, whether external or internal, and this principle had served it well in times of crisis. Assad also saw the initial response to popular protests in Tunisia and Egypt, and he likely concluded that by not cracking down forcefully, those rulers appeared weak and encouraged protesters to broaden their demands. So when his own people revolted, Assad decided to hunker down and crush the uprising.

At the start of the rebellion in 2011, Assad used Islamic militants to destabilize his opponents, as he had done nearly a decade earlier in Iraq. The Syrian regime released hundreds of al Qaeda activists and other militants from its prisons, and they went on to become leaders of Islamic State and other jihadist groups. Many of those militants ended up fighting Assad’s regime, but they also became the focus for Western leaders worried about jihadist attacks in their own countries.

Throughout the presidential campaign, Trump said he wanted to avoid direct U.S. involvement in the Syrian conflict, which has expanded into a regional proxy war. Russia and Iran, along with Shi’ite militias like Lebanon’s Hezbollah, helped Assad consolidate control and regain territory he lost to the rebels. In December, with intensive Russian air strikes and Iranian ground support, Assad recaptured the rebel-held sections of Aleppo, Syria’s largest city. It was Assad’s biggest victory since the war began.

After Trump was elected, Assad became more confident because Trump had pledged to end U.S. support for rebels fighting the Syrian regime and direct most American efforts to fighting Islamic State. Assad and his allies have rarely fought directly against the jihadist group, which established its self-proclaimed capital in the eastern city of Raqqa.

Since November, the United States has helped mobilize nearly 50,000 Kurdish and Sunni Arab fighters to encircle Raqqa, and cut it off from all sides. The offensive is supported by American air strikes and hundreds of U.S. troops. But Trump’s missile strikes could slow the offensive to oust Islamic State from Raqqa and other parts of eastern Syria. The Pentagon coordinates with Russian forces in Syria, especially in launching air strikes, and Russian officials threatened to suspend the communications hotline after the April 7 U.S. attack on the Syrian airfield.

Assad has now suffered a setback because of the American attack, but Trump’s limited intervention is unlikely to change the course of the Syrian war – and Assad will continue his scorched earth policy against rebels and civilians, even if he will now think twice about using chemical weapons.