This is interesting topic. I am a fan of Glubb Pasha and find his theory interesting but human affairs are complex. Let's check some facts.
The British Empire had values in its homeland but lost its military strength and ability to hold foreign lands in World War Two and the much larger and strategically located US took its place to unite and rebuild the West.
The US stem from the American Revolution movement in 1775 when settlers in North America demonstrated cultural sophistication and the ability to handle the British Empire in open battles. The US proceeded to defeat other rivals in the region such as the Mexican Empire and numerous Red Indian tribes in an effort to expand its territory.
American history is also dark but American approach to global affairs is different from that of the British Empire. The British Empire did not grant much autonomy to colonies but the US allows friendly countries to create their own political setup and economy and is willing to fight for countries it finds valuable around the world. The first demonstration of this kind was in the Korean War wherein US-led forces fought to preserve South Korea.
The US became a world power when it defeated the Spanish Empire in war and liberated a number of Spanish colonies such as Cuba, Puerto Rico, the Philippines, and Guam in the process. The US also defeated Imperial Japan in the Pacific War.
Both the British Empire and Imperial Japan sought to colonize China and treated Chinese badly but the US did not expand war to China in the Korean War.
The American Empire has created a progressive World Order in comparison to the British Empire that is apparent in OECD. The US also support international institutions such as WB, WHO, UN, and IMF to help all countries in different ways.
So what we have as an alternative?
Soviet Union proposed a system wherein the state is supreme and has control on all aspects of life. Soviet nationals were lacking in freedoms that are found in OECD and the realization eventually set in. Related information in
here.
China has a hybrid system wherein the state is supreme but it allows Chinese nationals to do business with all, grow, and have quality of life. But the state can apply control and enforce discipline in any province in the manner it see fit.
But Cold War between superpowers is an issue that warrants attention and careful foreign policy measures.
Decadence has become a global phenomenon due to different causes in different countries. Some countries are underdeveloped and have corruption due to elite capture and broken education system. On a broader level, there is a drop in understanding of religious teachings and the focus have shifted to politics. There is politics in everything and it creates differences instead of promoting understanding and balance. Cold War between the US and Soviet Union was another factor in promoting politics in Islamic countries that reduced unity and pit countries against each other to the benefit of those who were pulling strings from behind.
Allah Almighty have warned in Surah al-Isra that virtually any civilization that has corruption and arrogance can face hardships and fall. The British Empire homeland was civilized but oppressed others on a global scale - this system lasted 200 years but met its end in World War Two. But corruption and arrogance is a common theme in Africa, Asia, and South America. There is also much conflict in these regions, which is not surprising.
American values have certainly declined after World War Two and the US have made some controversial foreign policy calls such as in the case of Vietnam, Iraq, and Palestine. The US destroyed much of Vietnam in war before realizing that South Vietnam is not worth fighting for. The US had a straightforward and better rationale of overthrowing oppressive Saddam regime in Iraq but came up with the WMD rationale for intervention in Iraq - this was absolutely stupid and damaged American credibility. The US finds Israel valuable but does not have a solution for the ongoing Palestinian issue. There is more but I don't want to type a lot. The American Empire is not perfect or cannot satisfy all.
But the US has democracy and allow American nationals to innovate, grow, and have a point of view. American power also stem from its professional institutions that do not undermine each other.
So which country is better and will last, only Allah Almighty knows.
Allah Almighty disclosed in Surah al-Isra that the Children of Israel will regroup in the Middle East at some point after destructive wars that ruined them. WE can see this in current times.
So what is in the future?
Not sure TBH. Israel may (or) may not last. The US may (or) may not last. China may (or) may not last. Heck, do we know for sure that Pakistan and India will last? Anything is possible. There can also be catastrophic event(s) that might reshape mankind in profound ways in the years to come.
Allah Almighty disclosed in Surah Ad-dhukan that there will be age of smoke that will engulf mankind in the End Times. How this will come to pass remains to be seen. Global warming? Volcanic activity? Nuclear war? Comet strike?
So all should take stock of their beliefs and biases, and strive for better solutions while they can.
