What are the four famous but most useless military defense lines?

The existence of things always has its rationality, but there are always a few unexpected examples, just like military defense lines. It is our most important fortifications and the key to our mastery of the battlefield. But if it doesn't play its due role, its existence seems to be like chicken ribs, which has no practical significance.

Military defense is indispensable in the war. The Great Wall of Wan Li was built in ancient China to resist the invasion of Xiongnu and other minority countries, which is a national barrier. Therefore, in modern wars, many countries have invested huge sums of money to build an impregnable military defense line, but they have not played their role and become international laughingstock.

Maginot line is the most famous of these laughingstock military defense lines. It belongs to the Franco-German border defense line. During World War I, France was attacked by Germany, and most of its territory was occupied by Germany. After World War I, this military defense line was built on the French-German border, with a total length of 390 kilometers and a cost of 5 billion francs. But when World War II broke out, this line of defense didn't work, and the Germans bypassed maginot line.

However, Germany also made mistakes. As mentioned above, the Germans invaded France by bypassing maginot line. In order to prevent the European allies from landing at that time, Germany built a 2700-long Atlantic barrier. Germans are extremely tenacious on the battlefield, and the effect of blitzkrieg is very remarkable. But after the defeat of Germany, this defense line is still in the unfinished stage.

Israel is a small country in the Middle East, but it has a complete army and is developing rapidly. However, it still makes the same mistakes as other countries in military defense. The Palestinian defense line built in the third Middle East War used a variety of armaments, and mines and other explosives were placed on the front line in an attempt to strengthen the defense of the defense line. Because it was built with sand, it was broken by the enemy in just five hours under the impact of the water gun.

Of course, our country also has a weak military defense line, which was established on our land to resist the Soviet Union when the Japanese occupied the three northeastern provinces of China. The construction of this defense line consumes most of Japan's national strength, and this defense line is the Tiger Head Fortress. This is one of the crimes of Japanese aggression against China. Fortunately, this line of defense collapsed under the attack of the Soviet Union, making it meaningless.