US President Donald Trump has long been a vocal critic of his predecessor Barack Obama, calling him "a disaster" and slamming him repeatedly for being "weak" and "ineffective" on a number of foreign policy issues during his election campaign last year.

This morning, Trump had the opportunity to demonstrate to the world that he was actually right about Obama - especially in terms of his inaction on Syria - and that the fear-mongering of the potential global repercussions of any US military action against the genocidal Syrian dictator Bashar al-Assad turned out to be nothing more than an exaggeration.

Days after Trump said that Assad had gone "beyond a red line" when his forces used suspected sarin nerve agents to kill dozens of men, women and children in Syria's northern Idlib province, two US Navy destroyers in the eastern Mediterranean fired 59 cruise missiles at the Shayrat airbase near the west-central Syrian city of Homs. According to reports, US strikes completely disabled the base, destroyed at least 14 Russian-made Sukhoi warplanes and killed six regime soldiers.

Changing strategy

Of course, Trump's references to Assad and red lines were a direct attack on Obama's infamously weak statements regarding Assad's use of chemical weapons.

In 2013, just before the Syrian regime gassed the town of Ghouta near Damascus, killing more than 1,000 civilians, Obama declared that the use of chemical weapons by Assad would cross a "red line" and might trigger a US military response.

The Obama administration failed to enforce this red line and so Assad continued to use chemical attacks throughout his war to maintain Baathist power, with Russian and Iranian backing.

Trump's decision to order a direct military strike as a punitive measure against the Assad regime was the first of its kind, and has thrown the regime and its Russian and Iranian allies an unexpected curve ball.

The Obama administration had ceded the strategic initiative to the Russians and the regime, allowing them complete freedom of movement in Syria, but Trump's surprise decision to decimate a Syrian airbase reminded the actors in the Syrian war that the United States is still the world's preeminent power, both politically and militarily.

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Following the strike, all that the Russians and the Iranians have been able to do is huff and puff, while traditional US allies such as Saudi Arabia and Turkey have rallied towards Washington once again, after years of fraying ties and weakening relations.

If Trump plays this correctly, he will restore regional faith in American leadership and ability and be able to gather willing allies to create a balance against not only Russian militarism, but also Iranian expansionism.

While US' relations with its allies have not exactly been reset, Trump's decision is likely to encourage them to think that his era will be different to the one that preceded him. Under Obama, both Saudi Arabia and Turkey launched interventions into Yemen and Syria respectively, seeing their strategic interests threatened and abandoned by US intransigence.

If Trump plays this correctly, he will restore regional faith in American leadership and ability and be able to gather willing allies to create a balance against not only Russian militarism, but also Iranian expansionism.

The Assad regime and its backers are likely to take cautious steps to react to this explosive development. The complete freedom of movement granted to Russia and Iran by the weak Obama administration has now been threatened by a new president, who is seemingly unpredictable. Just days ago, the removal of Assad was not a priority for the US, yet now the US policy on this issue has changed in a spectacular fashion, with Secretary of State Rex Tillerson saying that "steps were under way" to remove the dictator and an Assad airbase being smashed this morning.

Probing US resolve

As a result, the pro-Assad alliance is going to have to think carefully about how to respond. Clearly, 59 Tomahawk cruise missiles almost wiping out an airbase is not a small message, but Trump did not target the regime's chemical munitions themselves - arms that were supposed to have been destroyed following the 2013 Ghouta massacre.

The US has also not yet imposed a no-fly zone, or taken similar measures to prevent Assad's warplanes from striking civilian targets. This may have something to do with Russian-provided S-400 surface-to-air missile batteries that place most of Syria under an anti-airstrike umbrella from Hmeimim airbase near Latakia.

Nevertheless, the Russians, Iranians and indeed the regime will feel the need to respond. Aside from the urgent Security Council meeting called by Russia that will take place over the weekend, their response is likely to involve an increase in the use of conventional munitions on opposition sites that will conveniently be branded as "terrorist positions".

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The pro-Assad coalition will try to see just how much damage they can cause using intensified conventional attacks before possibly risking a further strike, if any comes at all.

The Trump administration, in the meantime, will either revert back to a more passive stance on Syria and continue its almost single-minded focus on the threat posed by the so-called Islamic State of Iraq and the Levant (ISIL, also known as ISIS) terrorist group, or will seek to up its support to friendly Syrian factions, who can at once serve as partners against ISIL while simultaneously providing balance against the Assad regime and Russo-Iranian interests in the country.

Could this mean the Syrian Revolution, seemingly on its last legs after the loss of Aleppo late last year, has been given the kiss of life with the opposition being able to bring more to the table to negotiate a more favourable outcome to the end of the war? Only time will tell.

Tallha Abdulrazaq is a researcher at the University of Exeter's Strategy and Security Institute and winner of the 2015 Al Jazeera Young Researcher Award.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policies.