In a university commencement speech over the weekend, US Secretary of State John Kerry ridiculed Republican presidential candidate Donald Trump's plan to build a wall on the Mexican border. He told the students to get ready for a borderless society. He also said that in this age it is unrealistic to believe that a wall will keep out those who would seek to harm Americans inside our borders. He has a point in that, however why not think this through completely and consider whether those who would attack us are motivated by US foreign policy? If it is not true that they just attack us because we are rich and free, and if walls cannot keep them out, isn't it time to take a hard look at our interventionist foreign policy and ask whether it is actually making us less safe and more vulnerable to attack?