Loyalty and duty.
Turkey joined Germany in World War 1
Maryland was a border state which remained in the Union but would have soldiers fighting on both side.
The joined the Union. Lincoln's diplomacy was successful.
the border state
The Border States were a key part of the US Civil War. They were slave states that did not join the Confederacy, it was important for the Union to prevent that they did not secede and join the South.
Southern border of China
I bealive that it was Virginia. E.N.R.
Bolivia border with Peru to the southeast with the departament of Puno in Peru join the titicaca lake,
Laredo is safe at the border on the United States side.