Neither the USA nor Mexico claimed the island.
But unlike most states Texas retained its sovereignty when it joined the Union.
Fenton Island is about to become part of the Free State of Texas.
“Fenton Island is about to become part of the Free State of Texas.”
And it may, but hasn’t yet. And it isn’t new news.
“…170-acre Mexican cartel-controlled island in the middle of the Rio Grande River…”
It is illegal for any state law enforcement organization to step outside their and US borders, that is the federals job.
There is confusion if the island is controlled by the US or Mexico and historically neither has taken credit for it. And the island has been under the control of cartels for many years.
U.S. and Mexican military and law enforcement alike avoided the diplomatic risk of working on the other’s possible territory without requisite permission.
https://cis.org/Bensman/Texas-Seizes-Large-Sanctuary-Island-Campaign-Against-Cartels
The mini islands have formed off the riverbanks in rural Starr County in deep South Texas, and have become a hiding place for drug smugglers and human traffickers, and even spots from where U.S. agents have been fired upon.
Note the date on that is over three years old.
Thus the rangers entered a sovereign reservation outside the US to control it by force. And that is an invasion.
wy69