However, neutral ships and aircraft do not become lawful targets merely because they enter such zones. Russia would only have had a reasonable claim to use force against, or interfere with, the US drone if it posed an imminent threat of an armed attack or was otherwise a legitimate military target during an armed conflict.
For this to be the case, the US drone would have had to be taking direct part in hostilities, and it is known that the MQ-9 was unarmed.
ON SOLID GROUND IN THE SKIES
Assuming the US account is correct, it would not be the first time that a country has interfered with a US surveillance aircraft in an unsafe manner and effectively downed it.
In 2001, a Chinese fighter jet bumped into a US signals intelligence aircraft that was operating 113km from China’s Hainan Island. The US aircraft was damaged in a way that forced it to make an emergency landing on Hainan, while the Chinese fighter jet itself crashed.
At the time, the United States asserted that international law, including the “due regard” principle, permitted the United States to conduct surveillance flights in China’s exclusive economic zone, which the US considered to be international airspace. China didn’t and detained the 24 US crew members, demanding an apology from Washington.
Since then, China has intercepted Australian and Canadian aircraft that were engaged in routine surveillance in international airspace, prompting complaints similar to those the United States is making now.
In both the China case and the recent Black Sea incident, the United States has taken a consistent, widely shared position on the use of international airspace. As such, I believe it is on solid ground in objecting to Russia’s actions as unlawful.
Ashley S Deeks is Professor of Scholarly Research in Law, University of Virginia. This commentary first appeared on The Conversation.