I am biological life, and in myself I see an example of what is technologically possible in terms of intelligence, and most likely vastly surpassed. There is a relentless quest right now to create intelligent machine life, that outdoes biological life in terms of intelligence, and then comes the big IF, if this machine life will be kind to biological life, or simply surpass it and displace it.
In the present state of world affairs I don't think you can put a stop to AI research. If we in the US won't do AI research, the Chinese will do it, and get ahead of us, militarily. As long as we don't have a united world, and there is power competition that could potentially spill over into military conflict, AI research will not be stopped. Also as long as we don't have a united world, there is a possibility of world war, especially when power entities roughly equal in strength arise, as is the case of the China/Russia/North Korea/Iran and the Muslim world vs. USA/Western Europe/Israel/Taiwan with Africa and South America as sideline spectators. WWII left much of the world in ruins, needing rebuilding, except the USA, which fast became the dominant global economic and political power, with its currency, the dollar, becoming the global currency. However now China has risen to comparable status, and wants to assert itself and its vision too, and sometimes this clashes with the US vision of how the world should be run. When there is no single dominant global power, there is room for power competition, disagreement and military conflict, ultimately leading to a WWIII.
At the close of WWII the UN was created as a conflict mitigation forum, where the world could come together and work out differences, but it is not doing its function, not serving its purpose, instead it is like a political circus, symbolic forum that cannot decide, and even if it sometimes decides almost unanimously, it has no grip, no bite, no traction in the real world. It can issue decrees that member states can ignore at whim, because it has no enforcing power. Real power is only economic power, the power of money, that can buy military power, power of the gun. The UN is like a judge slamming a hammer down as a verdict is pronounced, but the guilty parties can totally ignore it and do as the please and go freely, because the judge lacks a law enforcement agency using weapons to carry out the verdict. The UN does have some meager amount of troops contributed by member nations for peace keeping operations, and the only time it has significant military power is when some of its member nations carry out their own military whim under the aura and umbrella of UN approval as a coalition.
As a solution for the UN's design by committee unable to decide I suggest a centralized powerful leader figure, a global monarch, a single entity that cannot be in disagreement with itself. If there are two or more entities making a decision there is room for disagreement, room for conflict, and then you need an odd number of them two avoid stalemate situations. Imagine if the military was run by voting by the troops, for every decision, instead of voting on a unified centralized leader, a general, whose orders then everybody follows, except in special cases when there is room for mutiny. The UN is where every decision gets voted on, and it seldom comes to a unified agreement, especially when there are globally roughly equal sized opposing powers participating. What the UN needs is a monarch, that can decide. Monarchs has been how problems of leadership and need for unification have been solved in history, until their shortcomings, such as the lack of power derived from representation came to forefront. A Monarch may have a different self interest at hand which may not align with the self interest of the population he rules over and commands. But even in a democracy we still elect a single leader, a monarch, a president, whose powers are not unchecked, but significant. Congress functions as pork barrel politics where you can never pass a law without earmarks for a bridge to be built somewhere, to buy off and attain the sufficient number of votes to get a bill passed. Everyone in Congress pursuing their own self interest, or the self interests of the group of people they represent. If anything, the president is the most devoid of such localized individualistic state self interests when his function is to serve the interests of the whole nation. But when it comes to that his interests lies with the interests of the nation, not the interests of the world as a whole.
I suggest reforming the UN. Giving it decision power by instituting a globally elected monarch, a UN President, whose status is not just symbolic, but giving it a budget with which he or she can purchase military power. And, as her main function would be conflict resolution, and existential risk mitigation such as regulating or banning AI, bioweapon and nuclear weapons research, and her most important skills needed would be compassion and care, I would hope it would be a female that got elected. Her title would be "Mother", and all the world's people her symbolic children. Her job would be like Pontius Pilate, not the get involved in the internal affairs of the member countries, but take over their external politics. Pontius Pilate should have stood up and defend an innocent man, so this setup is not perfect, but the most pragmatic. She would have a say in internal affairs, inasmuch as ethnic conflict is concerned, and the Kurds could have their own representatives in the UN without having a country, and the Pashtun also, and she could decide on ethnicity related issues, but not whether a country is communist or capitalist or what kind of economic policies it wants to pursue.
As the state of the world affairs is right now, I would hope that a Chinese/American biracial/bilingual female would be elected as the president of the UN, with a male top adviser representing the other major racial groups. He would advise, but the ultimate decision would lie with her. While the long-term capital of the world should be in Jerusalem, at the present time that is not possible, and she should be part time resident in New York and Shanghai/Hong Kong. That she is female is not necessary, and a male "Father" could be elected, but I would hope a female would win the elections, where the whole world tunes in, like for the soccer world championships, and everyone would feel like they have a say and a stake in who leads them.
Next, the votes would be decided as such: a logarithmic population scale that penalizes overpopulation, say countries with at least 2 million people would get 1 representative, with 10 million 2, 30 million 3, 60 millon 4, 100 million 5, 1 billion 6. Then, more important than population would be GDP, which would be easy to measure based on who contributes how much tax to the global military fund. We often have meetings of G8 and G5, where countries like Mali or Togo don't participate, unlike at the UN where they get an equal vote to the US or China, which is silly, the tail wagging the dog. You would have, in the USA, local taxes, state taxes, federal taxes, and UN taxes. While at the present time states like Indiana or Ohio don't maintain their own separate military should they enter into a conflict with each other, instead they rely on the federal military and conflict is resolved at the federal level, in the long run the UN should have a military budget greater than any of its member countries, and in the long run member countries would not need to maintain their own military power instead rely on the UN the handle things globally. Now it's not nice to have to take orders from a central command and not do as your whim wishes like before, but it is necessary to avoid conflict, and create a stronger, more powerful, stable and safer world for everyone. Kind of like Richelieu helped centralize power in France to create a stronger France in view of Habsburg strength in neighboring regions, it was not nice for the landlords with their individual fiefdoms where they could do as they pleased, even enter into conflict with each other, but it was necessary, they had to start taking orders from a centralized unified single point command.
So population, GDP, and, at first I thought of land area, but that is the wrong criterion, we don't want Greenland/Denmark or Algeria have too much say in global affairs, but as biological life, I feel kinship with other biological life, and that should be taken into account for the voting power. Such as Amazon/Congo/Indonesian jungles destroyed along with their biodiversity due to human encroachment, or African elephants driven to extinction from human encroachment, that should be penalized, and biological life preserved in its greatest variety as much as possible, with the exception of diseases. In this sense the UN could support from its budget an agency of scientists assessing each countries' biomass, such as a 70kg human be on a scale 1 million, 1 ton of tree in the Siberian or Canadian tundra with low biodiversity a 1, but 3 to 5 in Honduras because of biodiversity factors, a ton of cattle 10, a ton of wild animals 50, etc. This scale would need refining, but countries like Brazil, Congo, Canada and Russia would get votes and representation by being caretakers of biomass roughly equal to the representatives they get from their population. Algeria and Greenland would not get much representation from this factor. Also, as I said, the GDP factor should be even more important than population or biomass, but individual countries could set their own tax rate, such as Netherlands might wish to buy more votes and representatives compared to its population, by simply setting their UN tax rate high, while China might feel their per capita income is not as high, and could set their tax rate lower. Whoever contributes most as taxes to the UN military fund gets the most representation, and ultimately the UN's military, or "law-enforcing" power should much overtake the military power of its individual member countries.
The UN president should be elected ever 4, 6 or 10 years, possibly reelectable 3 times, so a capable "Mother" could spend ages 40-70 in office and manage the world affairs, these details are up in the air. She would have executive power in that she would initiate actions, which then the representatives could vote on and reject if they get 80% no votes, something like that, and unless they can come up with an 80-90% no, she would get green light. But what happens to the world would be in her hands.