The Boston Marathon bombings could not have been foreseen in the case files of 8-year-old asylum seeker, Dzhokhar Tsarnaev, and his 15-year-old brother, Tamerlan. What should be questioned is whether US authorities do enough to integrate immigrant children once they arrive.
The US system for work visas hasn't changed much since 1965, despite fluctuations in the economy and in demand for foreign workers. Immigration reform must include more flexibility. One way is to create an independent body that regularly advises Congress on visa limits.