Why do nations go to war?

From the days of the Vietnam War to the most recent US confrontation with Iran, I have spent much of my life wondering why leaders choose to send their troops into war, creating destruction, misery and suffering for millions.

History has shown that most wars have been futile and costly wars of aggression. The 20th century was full of such conflicts, started and fought for a whole host of reasons - personal delusions of grandeur, foolish imperial ambitions, natural resources, ethnic divisions, the economic interests of a few, or a combination of all of the above. These are hardly causes worth asking people to fight, let alone die, for.

The wars of my lifetime have killed tens of millions, ravaged communities and left countries in ruins, with consequences that were often felt for decades. And to make things worse, most of these wars could and should have been prevented.

Clausewitz famously described war as “the continuation of politics by other means.” But first and foremost, war is an abject failure, if not a rejection, of diplomacy. This has become more evident in recent years, because we have gradually weakened, sidelined and disempowered the institutions designed to stand up for peace and broker peaceful resolutions. Who is left to do that now?

In 1945, the extreme human suffering of World War II, and the absence of functioning institutions to prevent it prompted the architects of the United Nations to state their determination “to save future generations from the scourge of war” in the the opening sentence of the UN Charter. More than 80 years on, it seems the farther the UN’s founding spirit fades from living memory, the more humanity defaults once again to warfare as a viable option to settle differences, no matter the cost. It’s a dreadful regression from the fragile consensus that once existed, however imperfect it may have been in practice.

Of course I am not saying countries don’t have a right to take up arms and defend themselves when they are attacked. Aggression must never be tolerated. I have long called for unwavering military support for Ukraine to counter Russia’s brutal assault on its sovereignty, identity and territorial integrity. I will continue to do that until a mutually acceptable solution can be negotiated. Even though Putin’s refusal to come to the negotiating table on fair and equal terms makes that feel like a distant vision at the moment.

When Saddam Hussein’s troops invaded Kuwait in the summer of 1990, the UN Security Council condemned the aggression near-unanimously in successive resolutions and ultimately, as a last resort, authorized the use of force by a multinational coalition under a clear mandate. It was a rare example of the global community standing together against an aggressor.

The war in Ukraine is one of many conflicts showing that this kind of unanimity is now out of reach. World powers seem unable to agree even on the most fundamental principles: condemnation of aggression, inviolability of national territory, protection of civilians, accountability for war crimes. The idea of universal values that sits at the heart of the UN’s mission has been devalued, to be replaced by geopolitical chess moves and opportunism. And I fear this will continue lead to failure after failure.

But it’s never too late to fix things and return to what has united much of humanity for many decades. And while some will dismiss this as "naive, globalist, world government" thinking, I like to think of it not only as a moral imperative, but also as a rather obvious question of cost and benefit. The cost of war will always dwarf the cost of seeking peace - from the enormous human toll, to military expenditures, or the price tag of war's lasting, unintended consequences.

The world needs peacemakers, not warriors. Idealists, not opportunists. And we need the functioning institutions that back them up. For those in power in the world’s capitals today, that would be a wise choice.