What if NATO United Into a Single Country?

So as always, population and land is the first thing we need to think about the reunited superpower. To start off, as mentioned in the blurb, a big total of 30 countries would unite to form the country with 27 of them being located entirely in Europe, 2 of them would be located in North America, and the last remaining one, Turkey, straddling between Europe and Asia.
As a result of having so many countries making up the union, the land area controlled by NATO would be gargantuan, standing at 10,344,129 square miles (26,791,171 square kilometers) which would easily make it the largest country in the entire world dwarfing what seemed like colossal entities of Russia (6,323,142 sq miles) and an independent Canada (3,511,022 sq miles).
Like its monumental land area, NATO would also have a massive population mainly due to the significant population centers in Europe and the US. Taking all of this into consideration, the total population would stand at 951,214,086 people. This is huge and would make it the 3rd most populous country in the world, still though remaining well behind the usual competitors, India (1.38 Billion) and China (1.439 Billion).
Now we come to the difficult parts, deciding on a capital city. A capital for a united NATO would not be an easy choice as there would be many, and I mean many rightful capitals for the country but my choice and probably the most likely decision would Brussels, in Belgium, as the city holds very significant historic importance to the alliance and is actually where the current NATO headquarters is located in. However, as always, Brussels would nowhere near make it into the top 10 most populous Urban-Areas within NATO. Instead, New York City, located in the eastern United States, would be the most populous city in the country with a massive population of 21,800,000 compared to Brussels' puny 2,700,000. Nonetheless, here would be the rest of the top 10 largest cities within the country:

As well as being a population hub and a land giant, NATO would also be an economic powerhouse. In fact, the country would be so economical that the nominal GDP would stand at a whopping $44.444 Trillion or 57% of the entire world's GDP! This would be much more than enough to put it in 1st place, in terms of nominal GDP, having double the amount of that of an independent United States ($22.68 Trillion) and having nearly triple that of China's ($16.64 Trillion).
The living standards of the country would also be very high standing at a respectable, nominal GDP Per Capita of $46,723. This would be enough to put in 23rd place, in terms of living standards, just in front of an independent United Kingdom ($46,344) but also remaining just behind New Zealand ($47,499).
As well as this, NATO would also control some of the largest oil reserves in the world, located in the United States, which would make them a big trading partner on the world stage.

Focusing on religion now, NATO would also be home to many religions with the largest followed faith being Christianity at 52% of the population, split between 26% Catholic, 20% Protestant, and 6% Orthodox. The next largest block would be Islam at 7.8%, split between 7.4% Sunni and 0.4% Shia. Hinduism would make up the last major religion with 0.2% of the population adhering to it and finally, the remaining percentage of the population would be Atheist or Irreligious, standing at a huge 40% of the population.
Moving on to the ethnic groups of the empire, Europeans would be the largest ethnicity in the union with a huge majority of the population at 74%. People who identify as exclusively white would make up the largest minority at 14% of the population, 2% would be Mestizo, Caucasoid's would make up 6% of the population, and the final 3% would be a mix of various other ethnic groups.

Finally, we move on to what NATO was made for in the first place, military. To start off, this complete superpower would, united, possess a massive 3,258,000 active-duty personnel. In addition, it would also possess another 2,774,000 troops placed in reserves bringing its troops to a huge total of 6,032,000! This would make it have the third-largest total military troops in the world, only behind those of South Korea's (6,708,000 troops) and North Korea's (7,769,000 troops).
As well as formidable manpower, NATO would also have by far the largest military budget of $1.115 Trillion (this is actually larger than the entire Nominal GDP of most countries in the world). This budget would nearly double that of an independent United States' budget ($778 Billion) and would nearly quadruple that of China's ($252 Billion)!
Lastly, NATO would also become a Nuclear power, inheriting all of France, the United Kingdom, and the United States' nuclear arsenals. With all of this taken into consideration, NATO would have an estimated 4,450 nukes which would make it have the 2nd largest nuclear stockpile, still though much behind Russia's estimated 6,000 nukes (This is however strongly debated).

Overall, if NATO united into a single country, it would be a huge threat to its enemies such as Russia, China, and Iran, and would definitely become one of the most significant powerhouses, in both economy and military, capable of dominating the world stage. Like every empire/organization in this series so far, it is completely impossible to accurately predict NATO's future in the world but there is no right or wrong answer to the question; will Russia and China just straight away initiate another world war or will they take a more calm and diplomatic approach to this newly emerging country? NATO would also need a bold and tactful leader to guide it in its path to global great power and in my opinion, the only person capable of doing such great things is MG17, the blog emperor himself! Anyway, if you have any new suggestions of other empires to do in this series, please let me know. But for now, I am going to hold a democratic vote for which one I should do next. Here are the options:

Japanese Empire | Khmer Empire | Tibetan Empire | A Chinese Dynasty | Yugoslavia

Finally, thank you all so much for reading and goodbye! :)