Do international alliances always make the world safer, or can they sometimes lead to more tension?

In my opinion alliances usually make the world safer because if a country gets attacked, the other countries in the alliance will help it. Alliances offer security and influence. Alliances have many benefits, like shared intelligence, an example being that of countries like Australia, Canada, New Zealand, the UK and the USA.

However, alliances can also have flaws. For example, NATO, which is a group of 32 members, is opposed to all other military alliances and has helped keep the peace in Europe since 1945. But other countries may think it unfair for NATO to impose on them not to be part of a different alliance. Therefore alliances can sometimes create tensions, like the tensions during the Cold War between NATO and communist countries.