The media’s coverage of the current situation at the U.S.-Mexico border has largely revolved around President Trump, but we may need to take him and his rhetoric out of the equation in order to have a rational, fact-based discussion of appropriate steps to secure our border.

The simple truth is that unless we are prepared to cede the right to control who immigrates into the U.S., we cannot permit members of “the caravan” — the group of thousands originating in Central America — to enter. Former Presidents Barack Obama, George W. Bush, and Bill Clinton did not take a contrary position on this when faced with similar threats, and I don’t believe they would today. If we allow this caravan of migrants in, there will be many more caravans to follow.

But on purely humanitarian grounds, we should do what we can to prevent and deter parents with small children from making the dangerous 2,000-mile trek in the first place. And we do not deter this action by permitting those who made the journey to enter. That simply invites more to do the same.

The federal government is obligated to control our borders against mass migration. If it doesn’t, we will be back where we were 15-20 years ago, when nearly any alien who wanted (and about half a million annually) illegally crossed our border with Mexico and gained entry into the U.S. This state of affairs prevented any semblance of an intelligent immigration policy, let alone one that serves the best interest of the United States and its citizens.

The recent use of tear gas at the border, although it appears to have been justified under the circumstances, is something U.S. authorities would like to avoid. It would be preferable if the Mexican government would instead prevent crowds from getting to and massing at and near the border, particularly when there are large numbers who can potentially rush the port of entry at San Ysidro, as happened recently.

The Mexican government could do this by interdicting and turning back migrants from the Northern Triangle of countries of Central America closer to the Guatemalan border, or by simply entering into a "safe third country" agreement with the United States, similar to what we have with Canada. Such an agreement postulates that if a person is truly escaping death or serious injury in, say, Honduras, he must make his asylum claim in the first safe country in which he alights — that is, Mexico. So far, the government of Mexico, which is in the throes of a presidential transition, has been unwilling or unable to make such an agreement.

To achieve border control over the longer term, the best strategy is one that addresses and reduces both the push and pull factors: the push being conditions in the northern tier nations of Central America and the pull being permitting unlawful entry into the United States, including misuse and abuse of asylum claims. It is true that, based on apprehensions by the Border Patrol, fewer people are illegally crossing our border than in 2000. There were 400,000 aliens apprehended by the Border Patrol last year compared to 1.6 million in 2000, but it is hard to argue that 400,000 is an acceptable number. Understandably to most Americans it is not. Moreover, there is no question that asylum is being abused and that human smugglers and persons not legally entitled to asylum are exploiting the system.

Right now, the men and women of U.S. Customs and Border Protection, which includes the Border Patrol, must perform their mission, which is to secure the border of our nation under very difficult circumstances. In reflecting back to my days as commissioner, I am persuaded that my successor at CBP, Commissioner Kevin McAleenan, has an even tougher challenge than I had in the aftermath of 9/11. I applaud his leadership in these difficult times.

Robert C. Bonner is a member of the Pacific Council on International Policy, a former U.S. district judge, DEA administrator, and commissioner of U.S. Customs and Border Protection. He is currently a senior principal at Sentinel HS Group.