Nearly nine years after Maoist rebels signed a peace deal with the government of Nepal ending a decade-long insurgency that left some 16,000 people dead, the Himalayan nation is again gripped by political upheaval. More than 40 people have died in violent protests since August. On Monday, the government began rationing fuel to cope with shortages caused when Indian oil trucks carrying fresh supplies stopped at the border. The government accused India of imposing an economic blockade; India said the disruption was a result of mass protests in Nepal against a new Constitution.

At issue is the enfranchisement of historically powerless ethnic and caste groups. Nepal’s new Constitution divides the country into seven federal districts. But the Madhesi ethnic group, concentrated along Nepal’s border with India, and ethnic Tharus complain they are not adequately represented, even though they are a significant part of Nepal’s population. Rather than demonstrate flexibility and negotiate greater inclusion for these groups, as the United States and India have advocated, Nepal’s constituent assembly approved the new Constitution without making any concessions.

There is a real risk now that a historic opportunity for national unity and healing has been squandered. Every effort should be made to address the grievances of these groups, including amending the new Constitution to ensure their equitable participation.

One thing the government should do immediately is withdraw the army from areas where it had been deployed. It must also order an impartial investigation into all protest-related deaths, and hold all responsible parties accountable. Attempting to quash by brute force the frustrations of Nepal’s impoverished and long-disenfranchised groups could lead to further insurgencies that would rip the country apart. This could be catastrophic. Winter is approaching, and millions of Nepalese whose lives were upended by the devastating earthquakes that struck the country in April and May are still waiting for their government to disburse more than $4 billion in aid from foreign governments and development agencies it received more than two months ago.