Is it safer for a country to have many different allies or to rely on one very powerful relationship?

In my perspective, it is safer for a country to rely on one very powerful relationship than have many different allies. Even though many allies can provide broader support, it also increases the number of relationships that have to be managed and trusted. One of our allies might betray us and we might never know who it is. On the other hand, if a country relies on one very powerful relationship with another country, that country can become a reliable partner. The alliance will become easier to maintain.

For example, would you rather have one best friend or a lot of friends? In my point of view, I would rather have one best friend than many friends. The reason is because I could share anything with my best friend (because I trust him/her). However, I don't really trust normal friends with my secrets. Also with more friends in the circle, it will be harder to communicate properly. It is because not all people can have the same thought. It will create a misunderstanding between us and ruin the friendship.

The same goes to countries and alliances. Although I don't think a country should rely entirely on one very powerful relationship. It might lead to some consequences (like economic vulnerability, political influence, etc.).