The nationalism and the protectionism that was built into the Mexican Revolution in 1910 and that characterized the Mexican attitude to the United States for much of the 20th century were difficult to overcome. But that actually has occurred. And the cooperation, trust and confidence that have been built is not something that should be abandoned without great consideration for the potentially grave consequences to the United States.

The image and the costs of a Berlin-like wall or a Great Wall of China is something that the American people have not accepted to date.

We have to remember that information sharing is restricted by legal barriers and cultural barriers and by the notion that information is power and therefore should be hoarded so if you share information you can extract something in exchange. In today's digital online world, those who don't share information will be isolated and left behind. We need the data of other countries to connect the dots.

Migrants come up and no longer seek to evade the Border Patrol, but are actually left at the border by their smugglers. And they seek out Border Patrol agents or Customs and Border Protection officials to surrender to them and request political asylum. That's the way in which they get entry into a system that will eventually release them into the country.

The cry of "Make America Great Again" reflects accurately that, after the fall of the Soviet Union, the sole superpower status of the United States is coming to an end. For the first time since the second World War, we are not the sole dominant economy in the world. In large part this is because of the success of policies followed by the United States to create an environment, a peaceful period in history in which economies could grow and countries could benefit.

We should be wary, particularly with our closest friends and allies, of breaking down the trust and confidence that lie at the foundation of relationships.

We can't defend the country by looking at the borderline as the first line of defense rather than as the last line of defense. We have to secure the flow of goods and people by engaging with foreign entities. We assure our security by securing the flows as early as we can before they arrive and as far away from our borders as we can.