Western countries have an aging and declining population which is not fit for war. It is highly unlikely Western countries will be able to fight a war again the way their ancestors fought WW1 and WW2.
There is something you always skip, Western alliance is a collective force. More specifically, NATO is the military organization with the most detailed and complex coordination capacity ever created in world history. Also, don't be shortsighted by just looking at military capability, you need to focus more on science. Is there any other organization like CERN in the world?
Human resources, or rapid aging is an important problem, but but it is not an insurmountable problem. Some fellows from eastern countries, have a mistake to present this deficiency as an overly large problem.
The East's most skilled workforce still goes west. Your brilliant young which you raised with public funds, are dedicating 40-50 years of his/her life to generating profits for European companies and governments.
Not just the top layer; Immigrants from the east still work at the airports, infrastructure constructions, low-level public works, taxis and restaurants in these countries. The inability to create sufficient production for cheap labor and therefore the reaction of the low- and middle-income segments is related to the sharing of the state's social assistance qualifications. Europe's dilemma is caught between immigrant integration or the automation and artificial intelligence solution of low-income jobs. In this respect, the problem is more political. (edit: also, the easiest way to get permanent residency and citizenship in the USA is to join the military since a century. does the discrimination you suffer prevent Asians from joining the army?)
The riches of the world have flowed here for 200 years. Not only the underground riches of Africa, South America and Asia, but everything valuable and profitable flowed here. The demographic reports that you realize today have been in front of European scientists and policy makers for nearly 50 years. Don't they see what you see?
Two important issues are financial environments and academic capacity. Today, the banks of 8 million people Swiss' banks give loans to the infrastructure construction works or military procurements of 100 million-people countries. The academic publication and citation-gives to other scientific studies of the same 8 million Swiss are double that of many Asian countries of 100 million. Now consider this country as a tiny member of the western alliance and what the collective sum is.
Europe is getting old, yes. But as long as Asia's answer is limited to bearing a child, the balances will not change, only the conditions will change.
Military capacity, political tradition, scientific studies, financial structure; all these are phenomena that produce cumulative accumulation. If you can't catch paradigm breaks, the one who started accumulating 50 years ago will always stay ahead of the one who started accumulating today.
Asia must awaken its collective strength.