No human being can remain indifferent to the atrocities perpetrated by the Assad regime – apparently with Russian and Iranian support – in the town of Khan Sheikhoun.Initial reports and eyewitnesses testimonies coming from the Idlib province in Syria say that Assad’s forces used sarin gas against civilians, including infants and young children.Assad has a clear interest in spurring a mass exodus from one of the last remaining strongholds of opposition.And Assad and Putin seem to believe that the world will do nothing beyond issuing outraged declarations, particularly if the two deny any connection with the incident, as they have done in the best tradition of cynical dictators.It hasn’t escaped Trump’s critics that the attack comes just days after the Trump administration made it clear that replacing Assad as leader of Syria as part of any future arrangement there “is not a priority.” Clearly Assad has little to lose by once again crossing a theoretical redline.The moral answer to this atrocity is a swift, decisive and debilitating military attack that would wipe the self-satisfied smirk off the faces of Assad and Putin. Former IDF Intelligence chief Amos Yadlin was speaking from his gut when he said this week in an interview on Army Radio that Israel should launch a missile attack against Syrian warplanes in response.Yet with all the talk of the Jewish state’s unique imperative as a country born in the aftermath of modern history’s greatest moral crime against humanity, Israel’s options are limited. Even Yadlin later walked back his heartfelt declarations. Israel alone cannot intervene in Syria in a way that does not expose it to immediate dangers. Tens of thousands of Hezbollah rockets and missiles are positioned in southern Lebanon on Israel’s northern border. Israel risks exposing tens of thousands of civilians to their firepower.Intervention on the side of the rebels – and not just in a limited fashion in order to protect cardinal Israeli interests such as preventing arms earmarked for Hezbollah from being smuggled into southern Lebanon – could also pit Israel against Russia.This is not to say that the world should ignore what Assad’s regime has perpetrated in Khan Sheikhoun.Failure on the part of the international community to act against Assad would send out a dangerous message to hostile autocratic regimes in the region and throughout the world that no breach of human morality, no matter how outrageous, will elicit a response from the international community.More dangerous would be the ramifications for other international treaties and conventions on the banning of nonconventional weapons. In 2013, when Syria used chemicals against its populace and in so doing blatantly crossed then-US president Barack Obama’s redline, a Russian-backed deal was reached according to which Syria promised to dispose of all of its chemical weapons. By July 2016, there was abundant evidence that Assad had failed to abide by the deal and that the Russians knew this.The mullahs of Tehran are undoubtedly watching closely to see how the latest Syrian trampling of international conventions will play out. Lack of a reaction would embolden them to push the limits on the nuclear arms deal that is supposed to prevent Iran from developing a nuclear bomb for the next decade.Enforcing international conventions on the banning of nonconventional weapons is not only an Israeli interest due to Syria’s proximity, it is also an interest of world powers that do not want to see the proliferation of nonconventional weapons.Though all sides in the conflict in Syria are declared enemies of Israel, the circumstances of the Jewish state’s establishment mitigate against indifference to the plight of Assad’s victims. Though Israel does not have the option of direct intervention, our leaders should lead the call for a robust international response to Assad’s atrocities.At the very least, Israel’s lawmakers should be able to rise above petty partisan politics and convene a special Knesset plenum to condemn Syria.