Okay kiddo, let me tell you everything about the "Nuclear Umbrella".
Have you ever seen an umbrella that can protect you from the rain or sun? Similarly, the Nuclear Umbrella is a defense mechanism that can protect a country or its allies from nuclear attacks.
Now, what are nuclear attacks? Have you seen fireworks on New Year's Eve? They create a lot of colorful lights, smoke, and loud sounds. Similarly, nuclear attacks create a lot of fire, smoke, and very loud sounds, but they are much more dangerous and devastating than fireworks.
So, countries like the United States, Russia, the United Kingdom, and France have nuclear weapons to defend themselves against any enemy that might use them to attack them or their allies. The Nuclear Umbrella is the guarantee that the country will use its nuclear weapons to protect its friends from an attack.
For example, let's say you and your friends are playing in the park, and a bigger kid comes and threatens to beat you up. Just then, your dad comes and tells the bully that he has a lot of friends who will come and protect you. So, the bully gets scared and decides to leave. Your dad's friends are like the countries that have nuclear weapons, and your dad is like the Nuclear Umbrella.
The Nuclear Umbrella helps in keeping peace and stability in the world, but it's also a big responsibility, as the world leaders have to make sure that they don't use their nuclear weapons carelessly, as it could harm a lot of people and have severe consequences.