China has returned the underwater drone it captured in the South China Sea last week to the United States, even as both sides continued to spar verbally over the incident. 

“After friendly consultations between the Chinese and US sides, the handover was smoothly completed at midday,” China’s Ministry of National Defence said yesterday.

The Pentagon concurred, saying the drone was handed over to guided missile destroyer USS Mustin near where it was taken, 50 nautical miles north-west of Subic Bay in the Philippines. But it also criticised China for how it had “unlawfully seized” the drone.

“The incident was inconsistent with both international law and standards of professionalism for conduct between navies at sea,” Pentagon press secretary Peter Cook said.

The Pentagon had earlier said that the drone was being used to carry out scientific research when it was taken in international waters. 

In its statement yesterday, it urged the Chinese authorities to comply with their obligations under international law and refrain from efforts to impede lawful US activities.

…Security analyst Li Mingjiang of the S. Rajaratnam School of International Studies believed the drone was returned quite quickly, less than a week after its seizure, probably as both sides did not want the issue to disrupt bilateral ties.

“The Chinese military and especially the navy realised the drone was probably not particularly for the collection of sensitive military or naval information. So they probably concluded that the drone was not a big threat to China’s national security,” he added. 

He said it was also likely that Chinese leaders believed they had sent a signal to the US that, in the South China Sea, China would not back down no matter what pressure the US exerted on it, and that it would not tolerate US plans to deploy such drones in the waterway in future.