A number of faiths believe in life after death and adherents act accordingly as individuals. The Muslim faith in the afterlife is quite particular and commands a particular style of life. Muslims have to obey their religion's rules more closely to reach a life after death than do other religions that include an afterlife. A Christian can make his way to heaven by repenting all his un-Christian acts in life just before he's called upon to leave it. A Muslim cannot go to heaven if he has ignored Allah and his prophet all his life except in his last hour. He has to live his entire life as the Prophet had wished him to do. One's acceptance of suicide in the service of his faith is only one of the multiple aspects where he diverges from Christians.
Whole libraries attempt to explain one great religion by comparison to others, and it would take intellectual impertinence to try and summarise these here. It would nevertheless be to our advantage to ask questions about why Muslim behaviour seems to have such a great effect on contemporary history which we are obliged to accept.
The last great European war in which religion was at least as important as the other usual motives was the Thirty Years' War (1618-1648). People fought each other across Europe, for various reasons, including because one side of the various little wars that made up the Thirty Years' War was led by monarchs, bishops, and other great Catholic personalities, and the other side being Protestants. After this war, others followed for the usual reasons of territorial convoitises, but religious dispute was no longer a primary motivation. From 1980 to 1988, some three and a half centuries after the last significant European religious conflict, a major war was fought between Iraq and Iran, representing the Sunni and Shi'ite factions of the Muslim faith because of, although not exclusively, religious differences.
Using a broad brush, the Muslim instability of today is explained by its initial and brilliant success. Starting in the 7th century, Muslim rayonnement and power expanded across the north of Africa and most of Spain, while its culture and science, starting from a Greek heritage, became almost peerless in the Middle Ages. Muslim power in the Eastern Mediterranean was shaken by a series of Crusades, but this Christian offensive collapsed after having had its own initial successes. In its final stage, Muslim leadership and power was taken over from Arabs by Turks, and under Turkish leadership it had great initial success taking over Constantinople, the Balkans, and a greater part of Hungary, arriving just under the walls of Vienna. However, by the 20th century, the Ottoman Empire was rapidly declining, its Arab possessions having all emancipated, mostly because of the defeat of Turkey in the First World War.
After the subsequent rise of al Qaeda and the destruction of New York's World Trade Center, the American reaction with the hope of cleaning out Afghanistan seemed a natural reflex. As al Qaeda went mostly out of fashion among the terrorists, IS (Islamic State) was taking its place. However, IS is a rather different creature, because of its ambition to build on the al Qaeda terrorist "culture" in Europe and Africa with the establishment of a rogue state in territories in Syria and Iraq. This combination is not proving to be a national one.
Initially IS consisted of Sunnis opposed to the regime of Bashar al-Assad in Syria as well as with the government in Bagdad which is favouring (Shi'ite) interests in Iraq with a majority of (Sunnis) being born to being the majority and the governing interest in Iraq.
The various Sunni tribes established connections with what remained of the Baath party and the professional army officers who became unemployed with the collapse of Saddam Hussein's regime. This collection of different kinds found leadership among Sunni politicians and soldiers who were reputed to be impeccable Jihadists. It pleases to call itself IS and in addition seeks to unite in one state all Muslims and eventually the whole world, which would become Muslim itself. This "incipient" state is, as of today, funded by donations from very rich princes and Sunni businessmen from the Gulf states, but even more so by the control of medium sized oil wells in the Mosul region. These oil installations are currently the target of American and Allied bombing, which some have claimed to be promising and others ineffective.
The Jihadist "army" of about 70,000 or so is at the centre of a much bigger, but also much looser, force that consists of all the significant Muslim minorities in Europe, Africa, and South Asia. In these minorities, in all the world, experts estimate that about a tenth are sympathetic to IS, though not necessarily to its mad cruelty, and within that community a non-negligible proportion would be easily persuaded to sacrifice itself in perpetrating terrorist acts, even killing innocent bystanders to promote their cause.
Governments in non-Muslim countries react in two ways. They invest huge resources in "security" to prevent terrorist attacks against civilians and civilian targets, including the use of their armies that have other important foreign policy roles being neglected as a result. A terrorist attack would, as police experts estimate, seldom cost more than twenty to thirty thousand dollars, but can cause extra public expenditure of thousands of times more. There is surely no more profitable way for small Jihadist commandos to inflict material loss on non-Muslim countries. The effect on civilian morale and ways of life would be an additional, but not measurable, bonus for Jihadists.
For more on these topics, see "Freedom and Duties, the Uninvited Guests", by Anthony de Jasay, October 5, 2015, and "A Flood of Immigrants," by Pedro Schwartz, January 4, 2016, at the Library of Economics and Liberty. See also the EconTalk podcast episode Coyne on Exporting Democracy after War, April 7, 2008.
A more subtle effect on public life is likely to be on "political correctness". Responsible leaders of public opinion will fear the way people react to the multiplication of terrorist attacks, aimed at victims who have no quarrel with Allah. Political correctness would have to be colour-blind and do what it could to avoid any allusion to most or all terrorists as Muslim. The public resents the attempt of the politically correct to mislead them, and as a result is all the more ready to suspect any Arab of wearing an explosive belt. The net result is a rise of the "extreme right" parties and a resentment by those peaceable Muslims for the suspicion and adverse discrimination of which they believe themselves to be the victims.
All or most of the good cards seem to be in the hands of IS. Trying to neutralize them is quite likely to make their hand even stronger. Fighting in Syria and Iraq using only aerial bombing without deploying infantry is likely to leave the population favouring Islamic infantry as the lesser evil. Much political correctness is meant to show that the Islamic minority are good citizens like the majority, and terrorists are just terrorists (even if all happen to be Muslims). This will likely only make the majority dislike the minority, and then entice some in the minority to give a helping hand to the terrorists who would render them justice. It is hard to accept this conclusion, but it would at least merit some thought. Perhaps the only effective weapon against the terrorists is to lead a life that would just ignore them and make them fall out of fashion like any other fashion in human history.