Trump, of course, has been very wrong in the past about important issues such as President Barack Obama's place of birth and Mexican immigrants, but the Republican frontrunner is correct in saying that former Republican President George W. Bush did not keep the country safe during the 9/11 terrorist attacks.
The diagnosis that poverty, lack of education, or lack of opportunities have much to do with terrorism requires a fundamentally optimistic view of human nature. This diagnosis leads to the prognosis that all we need to do to solve the terrorism problem is to create societies that are less poor, better educated and have more opportunities.
The reason that Islamist militants can assert that jihad is necessary against the perceived enemies of Islam is that there is sufficient ammunition in the Quran to buttress their beliefs. The same could also, of course, be said for the Old Testament, which is full of scenes of violent death visited on the enemies of God.
European countries simply do not have the ideological framework the United States has in the shape of the 'American dream' that has helped to absorb successfully wave after wave of immigration to the States, including Muslim Americans who are well integrated into American society. There is no analogous French dream or German dream.
Anne Richard, a senior U.S. State Department official, testified at a Senate Homeland Security Committee hearing in November 2015 that any Syrian refugee trying to get into the United States is scrutinized by officials from the National Counterterrorism Center, FBI, Department of Homeland Security, State Department and Pentagon.