In the span of just a few days, US President Donald Trump appears to have met both his first true foreign policy crisis and his most challenging bilateral summit more smoothly than many had feared he might. Whether this turns out to be anything more than a symbolic victory, and whether it has an effect in the fight against terrorism and the effort to rein in North Korea, will depend on what he and his administration do next.

Trump was clearly justified in Thursday’s decision to order cruise missile strikes on Syria’s Shayrat airbase, from where the regime had launched a sarin gas attack on civilians earlier in the week. As a sombre Trump noted, the world could not let such a violation of the Chemical Weapons Convention — not to mention civilised norms — go unpunished. The strikes themselves were targeted and proportional; the US military says that Russian personnel at the airbase were warned ahead of time to avoid sparking a wider clash. Allies welcomed the move, and it should go some way towards deterring any future use of chemical weapons on the Syrian battlefield.

More broadly, the strikes should bolster US credibility in dealing with other threats, including Iran and North Korea. Whatever one thinks of the previous administration’s decision not to bomb Syria after its earlier use of chemical weapons, it was widely read as a sign of weakness. The leaders of both North Korea and its sponsor China — Chinese President Xi Jinping happened to be at dinner with Trump moments before the strike — must now consider more seriously the possibility that the US could use force on the Korean Peninsula if its red lines are crossed.

The US reportedly reminded the Chinese that they would go their own way if China chose not to be more helpful with North Korea. It would be better for everyone if both sides instead worked out a co-ordinated strategy, with the burden on China to tighten the sanctions noose around North Korea until it returns to the negotiating table in a more amenable frame of mind.

At that point, the US should be willing to discuss a freeze of the North’s weapons programmes, even if it does not lead immediately to full denuclearisation. Trump has learnt the value of missiles. He should know their limits, too.

Yet the strikes have not changed one thing. The US still lacks a strategy for achieving its stated goals in Syria: defeating Islamic State, ending the civil conflict and easing Assad from power.

Further pinprick attacks will achieve little, while deeper US military involvement would be widely unpopular in the US — and arguably illegal without congressional authorisation.

Russia, Syria’s most powerful backer, knows this well. When he visits Moscow next week, US Secretary of State Rex Tillerson will need to present a credible plan not only to eradicate the Islamic State threat, but to create a limited safe zone for Syrian civilians and accelerate Assad’s transition from power.

Tillerson’s mission will be to convince Putin that any hope of a US-Russia rapprochement will depend on how helpful the latter proves to be in Syria.