By Beatrice Fihn is Executive Director of ICAN, the winner of the 2017 Nobel Peace Prize.

There’s an adage I keep hearing when discussing foreign policy and security issues, that ‘good fences make good neighbours’. In other words, clear and strong boundaries are essential for nations to maintain peaceful relationships, and if you keep your own affairs in order you can prevent your neighbour’s troubles spilling over. This argument loses all meaning in the event of a nuclear war. Nuclear weapons do not respect national boundaries, no matter where they fall.

Nuclear weapons used anywhere would have disastrous consequences that would quickly ripple across the world and undoubtedly hit the people of the African continent, even if that conflict was localised thousands of miles away.

Just a limited nuclear exchange between India and Pakistan over Kashmir, for example, would cause a nuclear winter lasting 2-3 years, devastate food production and lead to the starvation of billions of people. Sound far-fetched? There are 15,000 nuclear weapons around the world, that scenario would result from the use of just 100 of them.

It’s not hard to see how Africa could suffer tremendously from a crisis in which they had no involvement. Africa’s food supply is intertwined with Asia’s. Nigeria, the biggest African nation, is now the third largest importer of rice in the world with India being a key supplier.

For decades a handful of nuclear-armed states locked the rest of the world out of their negotiations about our shared future. That changed last year at the United Nations where a vast majority of states adopted the groundbreaking Treaty on the Prohibition of Nuclear weapons

Put simply, the Treaty recognizes the grave humanitarian harm caused by these weapons and makes the possession of and threatening the use of nuclear weapons illegal. Once 50 nations ratify it, the ban on nuclear weapons will become international law. 69 have signed and 19 have ratified already.

But of those 19 states that have ratified, only one is from Africa. The Gambia became the first to deposit their official instruments of ratification this week. Many African states supported and voted for the Treaty at the UN, and 21 have signed, but they have not moved swiftly to ratify

Africa has been a leader on the nuclear weapons issue for decades. South Africa remains the only country to disarm after developing nuclear weapons. Most African states are part of the African Nuclear-Weapon-Free Zone Treaty. If the 40 states who signed and ratified that Treaty hastened their pace to ratify the nuclear ban treaty it would quickly enter into legal force.

Doing so will give African leaders greater control over their countries’ futures and ultimately provide more security to their citizens. Africa may be free of nuclear weapons, but the continent is not free of their effects.

Rather than ending that threat, some African states are enabling nuclear weapons development in ways they may not even realize. Global banks are helping fund a new generation of nuclear weapons being built to keep the nuclear threat alive for decades to come. Banks like BNP Paribas operate across Africa, where the bank offers services in 11 countries. That bank alone provides USD$ 8.6 billion in financing to companies producing nuclear weapons.

The Treaty on the Prohibition of Nuclear Weapons puts power back in the hands of these nations. It would obligate them to cease support for nuclear weapons development, including financing, among other steps that will make their people and environment safer.

No country is immune to the dangers posed by nuclear weapons. No far-flung corner of the world with offer adequate refuge from a nuclear war, no nation can claim immunity or neutrality from a conflict that involves nuclear-armed states.

So it is incumbent on each nation to seize control of their own destiny before it is taken from them due to geopolitical events that they had no part in. Each nation can do just that by joining the growing community of nations that are part of the Treaty that bans these horrifying weapons that have no military utility. Each nation can refuse to be passive hostage to the whims of a few men with their finger on the button; only a late night tweet or insult away from plunging us all into a nightmare of their making.

By ratifying the Treaty, African nations can reclaim their own destiny and make history on the side of reason and humanity.