What are the main defense targets of coastal defense?

The targets of coastal defense in the early Qing Dynasty were pirates and maritime dissidents. Long-term implementation of the coastal defense policy of "focusing on preventing it from leaving", it is strictly forbidden to emigrate and transport strategic materials overseas. The corresponding coastal defense system is mainly based on land.

The amphibious system, which is dominated by Haikou open-air battery and supplemented by small offshore warships, has dispersed the coastal forces. After the First Opium War, this decentralized coastal defense system was seriously challenged and destroyed. At first, the Qing court tried to repair it, with little effect. Later, the continuous coastal defense crisis forced the Qing court to change its strategic policy and change it to "focusing on preventing its entry."

Main advantages:

No matter what kind of border, it may become a place where the enemy invades. So there must be coastal defense. According to international practice, if a country has a maritime border, then the sea area within several miles or miles belongs to this country, and beyond this distance, it is called the high seas. The high seas belong to public waters, and any country's fleet can. And coastal defense is a defense institution to protect its own waters and national security.