TOKYO -- On March 12, as the coronavirus pandemic began disrupting daily life across the U.S., a Florida attorney filed a federal class-action lawsuit against the Chinese government, accusing it of a slow early response that caused "injury and incalculable harm" to people and businesses.

"China President Xi Jinping originally stated that he directed officials to contain the virus on Jan.7," the attorney wrote. "But it has since emerged that he did not do that, and that he actually waited until Jan. 22 to do direct containment, and still did not make any efforts public until it was too late."

Chinese authorities, "acting from their own economic self-interest and looking to protect their place as a superpower, failed to report the outbreak as quickly as they could have; underreported cases; and failed to contain the outbreak despite knowing the seriousness of the situation," the lawsuit said.

This suit, along with similar actions in Texas and Nevada, asserts that China is directly liable for the pandemic and seeks billions of dollars in damages. But whether China can be held responsible under international law, or whether it can be made to compensate those harmed by the outbreak, is far from clear.

COVID-19 is believed to have originated in the Chinese city of Wuhan. The first case was confirmed on Dec. 12, according to the city's public health commission. It was not reported to the World Health Organization's Chinese office until 19 days later, as "pneumonia of unknown etiology," and the seafood market where most of the earliest known cases were clustered was shut down Jan. 1.

Chinese President Xi Jinping inspects a research facility in Beijing. (Xinhua via Kyodo)

Chinese officials asserted until mid-January that there was no evidence of human-to-human transmission. A report by Chinese researchers later that month suggested that the virus began jumping between humans as early as mid-December.

Some in the U.S. say that China's delay in taking action allowed the virus to spread worldwide. The Politburo Standing Committee, China's top decision-making body, in a Feb. 3 meeting acknowledged "shortcomings" in the country's response to the outbreak and a need to improve.

If China did drag its feet, that would violate the International Health Regulations, which stipulate that parties must notify the WHO, "within 24 hours of assessment of public health information, of all events which may constitute a public health emergency of international concern."

Countries are also required to "continue to communicate to WHO timely, accurate and sufficiently detailed public health information available to it on the notified event."

The rules include a mechanism for determining whether a given event qualifies as an emergency, which was amended in 2005 to include any new infectious diseases, following China's sluggish response to severe acute respiratory syndrome, or SARS, in 2002 and 2003.

Key to the question of compensation is determining whether Beijing's handling of COVID-19 runs counter to customary international law.

Draft articles adopted by the International Law Commission, a United Nations agency, in 2001 state that the country responsible for a wrongful act "is under an obligation to make full reparation for the injury caused." This is the case even if the problem originated with local authorities.

Whether China can be made to pay compensation in this case is uncertain. "Monetary damages will be difficult to claim without proving a causal link to the harm done," said Hiroyuki Banzai, professor of law at Waseda University in Tokyo.

Plaintiffs would need to prove Chinese authorities had a scientific understanding of the risks yet failed to take reasonable caution, and that this led directly to Americans, for example, contracting the disease, he said.

"Even if there was a breach of the procedures set out by the International Health Regulations, the most that could be done is to demand steps to stop it from happening again," Banzai said.

The articles on international responsibility have been adopted only by the ILC and are not binding on countries in the same way as a ratified treaty. Taking the matter to the International Court of Justice would require Beijing's consent. The decisions to file the lawsuits in U.S. courts underscore the difficulty and of bringing such cases to an international venue.

Matters of national responsibility are often resolved through diplomatic rather than legal means.

"It's more feasible that the issue will be hashed out in debate through a multinational forum, like the UN General Assembly or the WHO, than that the responsibility issue will be settled in court," Banzai said.

"International society's mechanisms for punishing bad actors don't work that well," he said.