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

This curret issue is important to me because my country is part for an allience (called NATO). There is a problem with NATO because of Donald Trump. Will NATO be ruined?

The first example that supports my opinion is that alliences are extremely complex and build a lot of tension. Like NATO. NATO is a huge allience which many countries are in. It makes the world safer in most situation but in others they don't. For an example, NATO was safe until Mr Trump ( the president of USA) wants to take Greenlands oil but to do that he could possibly distroy NATO. This will cause tension because countries won't know who to defend.

The opposite view is that alliences dont't build tension and make the world safer. Many people belive its more effective working on your own. People think its more effective because you don't need to put in your money for other countries and that will build tension.

In conclusion, I think that internatial alliences do make the world safer but sometimes builds more tension when there is war and countries want each of resorces.

Thanks for reading