Asia, in particular China, has become one of the most dominant economic powers from around the world. With the large population, and extremely cheap labor force, many of the jobs are being outsourced to these Asian countries causing the money to be transferred over to the Asian countries. The number of skilled workers has dramatically increased in these countries and is beginning to out compete many western countries in the fields of science and technology.
It is an unfortunate fact that the West is currently on the decline. The West's low birthrate means it is an aging society which will eventually lead to lower economic output and higher costs for entitlements. In addition the West has largely lost its pride, purpose, and optimism. As long as this continues, the West's decline is inevitable.
Based on the current administration's policies, it is inevitable that the West will not be the global power it once was. With respect to military defense, the best way to have a strong defense is a powerful offense. However, to continuously cut military spending will only result in a weaker US defense. In addition, while we continue to weaken our capabilities, Eastern countries are strengthening theirs.
The West will never fully decline as a global power. While it's possible that China will continue to grow in power, the entirety of the West will not fade away. Great Britain used to be the greatest power in the world and while they declined, they are still powerful. That's how things will be for the West on the whole.