When the world’s most powerful nations fight, we need to know why they do so and what they can do to stop it.

The ability of non-state actors to take up arms has transformed warfare since the end of the Cold War. Weapons are more accessible, more varied and more destructive, while the ability of small groups of fighters to achieve strategic objectives and defeat supposedly superior forces has grown apace. The ability of all states to deploy high-tech capabilities that can disrupt and undermine enemy systems has also changed the way wars are fought.

Despite the changes in how we fight, the essential features of war remain unchanged. The motivation for fighting has always been a matter of acquiring critical resources, satisfying honour and ambition, and averting disaster. This has driven humans to organise themselves, even to the extent of sacralising violence and making it an activity worthy of being sacrificed for.

This organisation has been expressed in a range of ways, from the Greek Politeia and the Westphalian state system to modern mercenaries, militias, guerilla and terrorist organisations. But, despite the emergence of new forms of conflict, war remains, in the main, an organised affair involving the use of highly-trained state forces and often supported by civilian authorities.

Some people argue that this view of war is a false, limited and outdated one that does not fully understand why certain conflicts break out. These critics point out that culture has a strong influence on the rationalisation of conflict and that war is not just an instrument of policy but can be a form of expression of a particular identity, religion or belief. Others argue that Clausewitz’s analysis of war neglects the role that fear and emotion play in triggering a conflict and that this is a more accurate representation of the nature of war.

There is no doubt that the world’s militaries need to learn new strategies of conflict. The military establishment of America, in particular, has been struggling to come to terms with the changing nature of combat and has been seeking solutions that do not rely on historically anomalous imbalances in national power. It is a struggle that other great powers are sharing and one that is likely to continue. In a world where wars are a regular occurrence, the question is not whether the armed forces should learn to adapt but how they can do so in a manner that makes them more effective at preventing conflict rather than fuelling it. This will require a major shift in thinking from the old Cold War assumptions. Until that happens, there will be more wars. But if they are based on sound principles, it is possible that they will be less catastrophic than they have been in the past. For this to be true, there will need to be more investment in strategic culture and a willingness to recognise that war is now a different beast.