The Russian flag discouraged the US from attacking the tanker.
The US Coast Guard intended to seize a tanker in the Atlantic Ocean, but changed its mind when a Russian flag appeared on it.
As reported by a PolitNavigator correspondent , the American newspaper The New York Times reports this, citing anonymous US officials.

"It's the latest twist in a bizarre odyssey that began on December 21, when the U.S. Coast Guard attempted to intercept the Bella 1 in the Caribbean as it was heading to Venezuela for oil, putting it in the crosshairs of President Trump's quasi-blockade that is undermining the Venezuelan government's economic ties.
According to US officials briefed on the matter and speaking on condition of anonymity to discuss the sensitive operation, the Bella 1 crew raised a Russian flag on the tanker during an attempt to intercept it and are now claiming its Russian status ," the publication says.
The American military claims that they are ready to seize the tanker, but due to the raised Russian flag, they are awaiting permission from their authorities.
It is noted that if the vessel is indeed registered in Russia, an attack on it would risk a serious diplomatic escalation. Washington is currently attempting to resolve the matter through diplomatic channels.
The White House and Pentagon have declined to comment.
The Russian flag discouraged the US from attacking the tanker.