Officials reported that the Boston bombing suspects, Dzhokhar and Tamerlan Tsarnaev, were not sponsored by a terrorist organization. The evidence for this became stronger after Dzhokhar was questioned on his hospital bed and claimed that they were personally influenced by U.S. interventions such as the wars in Iraq and Afghanistan. The two were most likely "self-radicalized."
Former Congressman Ron Paul has been arguing for his entire political career that a highly interventionist foreign policy makes the United States less safe in the long run. It's because of something called blowback, which occurs when the use of force in foreign operations creates unintended consequences, often resulting in a retaliatory attack.
This is exactly what happened.
Granted, the brothers do not appear to have been directly harmed by U.S. foreign policy (more on that to come), but this drives the point even further home. This means that even if known terrorist organizations have limited capabilities to attack the United States, it is possible for independent radicals to take up the cause in their stead. Judging by the nature of terrorists and murderers who act on their own initiative, effective preemption would require nothing short of the machine in Minority Report. This is exactly the situation terrorists want, and this is exactly why it is so worrisome.
This is also part of the reason Paul advocates for a far more non-interventionist foreign policy. "If America indeed has something good to offer — the cause of peace, prosperity, and liberty — it must be spread through persuasion and by example, not by intimidation, bribes, and war," he contends.
You may not agree with the entirety of Ron Paul's vision or beliefs, but he consistently brings up important issues that simply aren't being addressed in the mainstream. Seeing as the United States cannot erase time or make everything better by apologizing to everyone, the best course of action is to rethink the strategy for how the U.S. deals with the world. It might be helpful to examine the "Team America World Police" complex and see if there are other ways for the world to defend itself.
At the very least, we should return to the history books and take a careful look at how U.S. foreign policy has changed the world specifically, so that we may better challenge the status quo. This is so that in the future, attacks like that in Boston will have not been a result of American chickens coming home to roost.
In order to incite a more substantial shift in public opinion, Paul recently unveiled his Institute for Peace and Prosperity. Here is his speech at the opening of the institute:
For more on this line of thought, check out this YouTube playlist explaining Paul's ideas in more detail (including explanations of how he is not an isolationist). More on the Boston bomber motives can be found here and here.