However, in the long term, Islam only poses a strategic threat if it is able to conquer & retain peoples with higher IQs than the peoples who now submit to its will.
The IQs of the arab & persian races are too low for regimes run by them [in and of themselves] to pose a strategic threat to the United States. [They can pose a threat when they purchase technology from higher-IQ races, such as the Chinese or the North Koreans, but they cannot develop the technology natively.]
Similarly, when the Muslims take control of Europe, the nuclear stockpiles of Britain, France, and Russia will quickly degenerate into worthless garbage, absent a human infrastructure of sufficiently well-educated, well-trained, high-IQ caucasians to maintain and service them.
So the challenge for Islam is to retain the high-IQ caucasians of Europe and to force them into some sort of dhimmitude wherein they design, build, and maintain these weapons systems in the service of Islam.
But if you want to see what happens when low-IQ third worlders take over a once vibrant, beautiful, thriving first world city, then I highly recommend you spend an hour or so following all the links at this fascinating website:
The Fabulous Ruins of DetroitTFRoD gives you a real good idea of what London, Paris, Moscow, Rome, et al will look like in 50 to 100 years, if present trends continue unabated.
Islam has always destroyed any society it has taken over. Spain was, at a very bleak period during the barbarian invasions from the North, the heir to Rome and had a great scholarly tradition, particularly in Southern Spain, which had been the birthplace of many Roman thinkers, writers and even emperors. Then the Muslims invaded; of course, they took credit for the all of the intellectual activity of Spain, and then bit by bit they stifled it. Because Islam was still in its very earliest phases at that point, it was not consolidated and probably more intellectual activity was allowed than would later be the norm - furthermore, the original Islamic conquerors had only themselves been recently conquered, and were from the intellectually advanced parts of the ME (such as Baghdad and Persia). However, these Muslims themselves were later conquered by more orthodox Arab Muslims, which is the constant story of Islamic countries.
Whenever Muslims are "infected" by the intellectual advances of the countries they conquer, their more orthodox brethren come along and remind them of the meaning of True Islam. Which, in short, brings death, intellectual death, and decay to any culture it subjugates.
There's been a lot of talk about how Europe will be mostly Muslim in demographics in about 50 years. This is only if present trends continue
The big issue in Europe will come to a head in 5 years, not 50. It will come as a result of the fact that such a high percentage of the Muslim immigrant population is on welfare. It will come when the taxpayers of Europe can no longer maintain the Welfare State.
The crash of the European Welfare State will be spectacular in its side effects
is the 'Detroit effect' seen in Northern Michigan now, or will it soon be?