At present, America is the only country to have had not only operational Gen-5 Stealth fighter, but also to have had fielded in actual combat zone. Russia is another country which along with China have active stealth aircraft programs. Only Russia and China are close to fielding Stealth aircraft in large numbers. Europe is dependent on F-35s, quantities vary from country to country. However Europe as a whole wouldn't any more than 500 F-35s as best case scenario. Largely due to budgetary constraints, which were caused by the 2008 Global Financial Crisis. And even though it has been a decade since the global financial crisis, the trend of clutching their fists full of money, won't ease up. Whatever the case, the stealth transformation of air forces around the world, would likely be gradual than rapid and the numbers, even though they look impressive, aren't that threatening. Europe will likely be using a mix of stealth and legacy fighters to make up for numbers. Few countries, even in Europe can afford to be an all aspects stealth combat fleet (fighters, fighter bombers and long range bombers). With that in mind, Russia and China are pacing themselves in the stealth aircraft development. In actual war, no country is stupid enough to go head on into a fight. As such, it is far more likely that stealth drones, commanded by A.I controls, in larger numbers, would be threatening to any nation. The race for A.I tech is at fever pitch, on all sides of the spectrum, and whoever gets their first, will effectively put to rest old generation warfare tactics. So as much as F-35s deployed by more Pro-West countries, sounds ominous, it isn't. Artificial Intelligence is what will kill the competition, period.