IMHO, the invention of the combustible engine and the almost simultaneous discovery of oil in the Middle East and N. Africa changed the geopolitical landscape. Both World War I and World War II devastated and weakened Europe and in effect, destabilized the Western world.
Some argue that the Allies access to oil in WWI was the decisive factor for Allied victory.:
http://www.saudiaramcoworld.com/issue/199901/prelude.to.discovery.htm
“The decisive difference between the allied forces of England, France and the United States and those of Germany, Austria-Hungary and Ottoman Turkey was thus not so much tactics or even leadership but oil supply. In addition to Anglo-Persian—which by 1916 was supplying one-fifth of the British Navy’s needs—the Allies had at their disposal the giant networks of Royal Dutch/Shell and Standard Oil of New Jersey. The Germans were less fortunate. When the Allies destroyed the oil facilities in Romania in November 1916, and then prevented Russia’s Baku fields from falling into German hands in August 1918, the war was unsustainable.”
Changing demographics such as population and the declining birth rate in Western nations has played a role too in the decline of Western influence in certain parts of the world.
Agreed. I would add that socialist anti-colonialism is now the prevalent belief among European elites and has been since about 1960. A few days ago I rented “The Battle of Algiers,” a 1965 film that won all kinds of awards and what we would call a docudrama about the French effort to suppress the FLN revolt in Algeria. Afterwards, I read an historical account of the War of Independence in Algeria (1954-1962). The film was mainly confined to the years 1956-57, but they got even this wrong historically. I think it gives a good insight into present European thinking about the Muslim world. The Algerian struggle was characterized by as much by religious fanaticism as nationalism, but nowhere does the film make show anything except religious piety. The idea that French government might be superior to that of the revolutionaries, was totally excluded.
Those pesky unintended consequences, again.
The importance of oil at the turn of the century, and its subsequent importance was also the poison that created almost all of the imponderable problems today, including the Middle East "crises", and the impossible position that Israel finds herself in.
Let's look at Israel for starters. The following site is the clearest and most concise example as I've ever seen, for a summary of how Israel's indefensible borders came to be:
History of Jewish-muslim Palestine
The US, attempting to fill the geopolitical vacuum after WW1 botched things royally. We alienated Europe, simply by being superior. We did not physically create an empire, but the popularity of our culture pissed everybody off. As did our success technologically and financially.
We pressured Great Britain into giving up the Suez Canal, we gave away the Panama Canal, and we have been pressuring Israel, since 1947 to play nice with the most inept, destructive and primitive culture on earth.
In the long term, islam has been more destructive to culture and history than all previous barbarian empires, as well as Nazi Germany and Imperial Japan. And they have been allowed to do their thing many many times longer, repeatedly.
What is the fundamental cause of all this irrationality? Oil.
In retrospect, the sandmaggots were given a gift by the West which has enriched a few corrupt families beyond the dreams of avarice, and accomplished little else; either to benefit their own people or for humanity.
In a "perfect world" The West should have simply said, "we made a mistake", take back the oil fields and send them off to their traditional wanderings.
Why didn't we? Peer pressure.
The desire to be seen as "good and noble", by other countries who would stab their own mothers in the back to get the cultural upper hand.
Did I mention I do not fear islam, but hold it in as low a regard as is possible?