We investigate the role of networks of military alliances in preventing or encouraging wars between groups of countries. A country is vulnerable to attack if there is some fully-allied group of countries that can defeat that country and its (remaining) allies based on a function of their...

The Global Methane Pledge to reduce emissions by at least 30 per cent by 2030, was signed by more than 100 countries at the COP26 Conference in November 2021. Reducing methane emissions from fossil fuel sources by up to 75 per cent by 2030 has been identified as an essential contribution to...