How difficult is it to build an aircraft carrier? Which countries in the world have aircraft carriers?

Aircraft carrier can be said to be the most difficult industrial system and the crown of a country's industry. First of all, you need the ability to build tens of thousands or even hundreds of thousands of tons of ships, and you also need to build a super power system. The aircraft carrier is not only large, but also needs strong power to be quickly deployed to the forefront. There are not a few ships larger than aircraft carriers, but not many can run more than 30 knots. Meanwhile, nuclear power plants are very, very difficult. At present, only the United States and France have mastered the manufacturing technology of nuclear-powered aircraft carriers, followed by catapults. At present, only the United States can produce catapults, and the difficulty can be imagined. Last but not least, carrier-based fighters are useless without fighter carriers, but fighters are already very sophisticated high-tech products, and it is even more difficult to take off and land on narrow aircraft carriers. Finally, aircraft carriers can not only fight by themselves, but also escort ships, such as destroyers and frigates.

Let's talk about which countries have aircraft carriers, such as the United States, France, Britain, Italy, Spain, Russia, China, Japan, India and Thailand.