Japan's geographic isolation as an island nation played a crucial role in protecting it from invaders, as its surrounding seas created a natural barrier. Additionally, the development of a strong naval force helped safeguard its waters. Historical events, such as the typhoons known as "kamikaze" that destroyed invading fleets, further contributed to Japan's defense against foreign attacks. Lastly, Japan's mountainous terrain made land invasions challenging, adding another layer of protection.
The Alps.
The Alps
You might protect your city-state from invaders by creating and maintaining a well-trained standing army. You might also create fortifications to block invaders.
In the past, the sea around Japan helped to protect them from invasion. However, after the USA developed the atom bomb, the difficulty of invading Japan influenced them to drop the atom bomb.
Oceans surrounding Japan protects it from invaders and provide plenty of fish.
to protect themselves from invaders
The desert helped Egypt by giving them protection from invaders. :) :0
To protect London from invaders.
To protect china from invaders
The British built forts mainly around their ports to protect the harbors from being bottled up by future invaders; such as at Singapore. The US also built forts around San Francisco Bay to protect it from future sea borne invaders (with Japan in mind, after the Russo-Japanese War 1904-1905).
hi
To protect china from invaders!