The border between the United States and Canada is 889 1 km. Why didn't the United States send someone to defend it?

The main reason is that the relationship between the United States and Canada is relatively good. Most of those borders are grasslands or forests, and it will cost a lot of money to build defense lines. Secondly, the United States and Canada are both developed countries, and there is no serious immigration problem, so there is no need to defend them. Only some areas are patrolled.

The border between the United States and Canada is the longest, with a total length of 889 1 km. This edge line is divided into 65,438+0,846. At that time, Canada was still ruled by the British, and this boundary line was recognized only after Canada became independent. There are mountains, forests, grasslands and cultivated land along this boundary line, and there is no need to set up defense lines in these special places. Neither country has troops on the border. If you drive, it will take four days and three nights to complete this defense line. If you really want to set up checkpoints and defense lines on this defense line, it will inevitably cost a lot of money and energy.

Secondly, relations between the two countries have always been good. Because they are both developed countries, and their cultures and languages are relatively civilized, they have not divided the two countries into many places with barbed wire and border walls. They just draw a white line or erect a stone tablet. On the border, you can hardly see any help. The two countries mainly set up some checkpoints at some cross-border international highway ports. Some passing vehicles and people will be checked, but in remote areas, such as streets and towns, no defense lines will be set up. The border people of the two countries can come and go at will, Canadians can come and go freely in the United States, and Americans can come and go freely in Canada.

Many countries set up defense lines mainly to prevent illegal immigrants, but these two countries don't have to worry about this problem. Even if there is no defense line, there will be people patrolling some areas. If there are illegal immigrants, they will still be banned from entering the country and charged a small fine.