The diplomatic spat between Beijing and Tokyo escalated on Saturday after a Chinese fighter jet trained its radar on Japanese aircraft.
Both sides gave conflicting accounts of the incident, which follows weeks of retaliation from China after Prime Minister Sanae Takaichi suggested Tokyo might intervene if China invades Taiwan.
“There is ample room for further escalation,” two CSIS experts wrote.
Japan has grown frustrated at the US’ silence, the Financial Times reported.
The White House’s new national security strategy, released Friday, no longer lists China as the US’ No. 1 challenge, and makes minor, but significant, linguistic shifts on its Taiwan policy that will be cheered in Beijing, analysts said.