I. Open covenants of peace, openly arrived at, after which there shall be no private international understandings of any kind, but diplomacy shall proceed always frankly and in the public view.
This point fails to exist today. Leaders of countries sometimes meet in private and without anyone knowing. They do not have to let the people of their country know what they are doing. Although they are probably frowned upon if they meet about something that is not of a good cause.
II: Absolute freedom of navigation upon the seas, outside territorial waters, alike in peace and in war, except as the seas may be closed in whole or in part by international action for the enforcement of international covenants.
This point still exists today. Anyone can set sail and roam around the oceans of the world. Each country, if it is along the water, controls a certain area of the ocean. However, past that it is free land, or in this case water.
XIII: An independent Polish state should be erected which should include the territories inhabited by indisputably Polish populations, which should be assured a free and secure access to the sea, and whose political and economic independence and territorial integrity should be guaranteed by international covenant.
This point still exists today because when Germany surrendered it gave Poland its independence. Today, Poland remains independent.
XIV. A general association of nations must be formed under specific covenants for the purpose of affording mutual guarantees of political independence and territorial integrity to great and small states alike.
Today there is a similar thing to the League of Nations in which this point created. The United Nations is also group of countries committed to maintaining international peace and security, developing friendly relations among nations and promoting social progress, better living standards and human rights. This is directly similar to the League of Nations because they are both peace keeping organizations.
I believe that the last point would be the most effective at preventing war because it helps keep peace between different countries all over the world. If there was no United Nations today I feel as though we may have went to war more and possibly be in a huge war in the near future.