The United States has charged Indian national Nikhil Gupta, a 52-year-old narcotics and weapons trader, for plotting to murder a prominent Sikh separatist, Gurpatwant Singh Pannun, a US citizen, in New York City. The indictment, which alleges that an Indian government official in New Delhi paid Gupta to arrange the killing, has cast a shadow over India's relationship with the US as well as the country's global image.

We have been here before. Just a couple of months ago, Canadian Prime Minister Justin Trudeau claimed that there were "credible allegations" about a "potential link" between India's government and the fatal shooting in June of Sikh separatist Hardeep Singh Nijjar, a Canadian citizen, on Canadian soil. India responded with outrage, demanding the withdrawal of 41 Canadian diplomats from New Delhi.

But whereas Trudeau could not prove that the Indian government was involved in Nijjar's killing, the US Justice Department is prepared to take its evidence to court. Among the damning details is one that seems to link the two killings: Gupta's handler in New Delhi allegedly sent him a video clip "showing Nijjar's bloody body slumped in his vehicle," which Gupta carelessly shared with the hitman he had hired.

The hitman turned out to be an undercover agent for the US Drug Enforcement Administration (DEA), stringing Gupta along so he could collect as much evidence as possible. Fortunately for him, Gupta seems to have carried out his assignment with extraordinary ineptitude, leaving behind enough evidence to incriminate everyone involved. His handler in New Delhi seems to have been little better, supplying Gupta with videos, messages, and detailed instructions. It all amounted to giving the US authorities the "smoking gun" that will likely convict Gupta.

The incident is curious for several reasons. For starters, it is inconsistent with Indian Prime Minister Narendra Modi's well-publicized priorities. Modi's government has gone to great lengths to promote India as a responsible global power, an influential voice in the G20, and a leader of the Global South, boasting to Indians that their country has become a "Vishwaguru," or "teacher to the world."

Under Modi, India has also been deepening its relations with the US, motivated not least by shared concerns about Chinese aggression. Orchestrating assassinations of citizens of friendly foreign countries - violating their sovereignty, the rule of law, and established international norms - seems an odd way to pursue these objectives.

That said, an assassination program would not be entirely out of line with Modi's carefully crafted domestic image as a tough, decisive, no-nonsense strongman who will go to any lengths to protect his people. Is it possible that elements within the Indian government acted on their own to bolster that image? The fact that Gupta was not a trained operative - or even a competent criminal - suggests that the effort to assassinate Pannun was not orchestrated at the very top.

The Gupta case is also curious because it suggests that targeting Sikh separatists is a high priority for India. But while there was a dangerous movement calling for a separate state of "Khalistan" in the 1980s (its members even blew up an Air India plane, killing all 329 people on board), separatism does not have any traction within India anymore, even in the Sikh-majority state of Punjab. It helps that, in recent decades, India has had a Sikh prime minister (Manmohan Singh) and army chief; two of India's last three ambassadors to the US have been Sikhs.

The cause of Khalistan is a fantasy nurtured by a tiny minority in the Sikh diaspora - hardly a threat that would justify jeopardizing India's global leadership ambitions, let alone its relationship with the US. This raises the possibility that Gupta's "handler" in New Delhi - whom the US Justice Department has identified but not named - was a rogue operative hoping to curry favor with the "tough guys" in Modi's entourage, rather than a representative of the highest authorities.

Of course, one must also consider the possibility that Indian officials, lulled into complacency by America's overt courtship of India as a counterweight to China, foolishly believed they could get away with anything. If so, high-level accountability is vital. Indians deserve better than vainglory and recklessness at the top of our policymaking apparatus.

Whatever comes next, heads must roll in Delhi. Someone will need to take the blame not only for planning such an operation, but also for behaving with such spectacular incompetence. More broadly, the crisis must be urgently defused and any damage to bilateral relations contained.

So far, India's government has not expressed the kind of self-righteousness it displayed after Trudeau's accusations. While its official spokesperson reiterated that conducting assassinations abroad "is contrary to government policy," he also announced the creation of a high-level inquiry committee tasked with looking into US concerns about bilateral security cooperation - in particular, "the nexus between organized criminals, gun runners, and terrorists."

The US seems interested in limiting the diplomatic fallout, even as it presses for an investigation. But the damage to the bilateral relationship could soon begin to materialize. For some months, there has been chatter in New Delhi that US President Joe Biden might be the chief guest at India's Republic Day celebrations on January 26, perhaps alongside the leaders of the Quad's other members, Australia and Japan. This scenario - which would be a major pre-election public-relations triumph for Modi - has been jeopardized.

In some quarters, India is now portrayed as a reckless global actor - a trigger-happy country with a hit list of foreign citizens it is determined to kill. That undoes decades of striving to craft India's image as a responsible power ready to take its place at the world's high table. When the Gupta case is resolved, India must show the world that it is truly devoted to the rule of law, at home and abroad.

From Project Syndicate