To the extent there is an emergency on the U.S. southern border, it is the result of a humanitarian crisis, not a security crisis, according to former Department of Homeland Security (DHS) Secretary Jeh Johnson.

He spoke in reference to recent statements made by President Trump and members of his administration, many of which blamed a supposed influx of illegal immigration for creating a "humanitarian and security crisis" near the U.S.-Mexico border. Mr. Trump has demanded "urgent action" from Congress, mainly in the form of billions in additional funding to support, among other things, the construction of miles of physical barriers along the frontier.

"There is so much emotion, politics and misinformation about immigration and about our southern border," said Johnson, who ran the U.S. government's third-largest department from 2013 to 2017 during the Obama administration. "So here are the facts: the facts are that illegal migration on our southern border is a fraction of what it used to be."

Johnson said that apprehensions of migrants attempting to cross the border into the United States had fallen to an annual level of between 300,000-400,000 – down significantly from a high of 1.6 million in fiscal year 2000.

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Meanwhile, Johnson said, "There's a humanitarian crisis in Central America that leads to the circumstances on our southern border today. And during a spike, you see local communities in, say, McAllen or Laredo or El Paso or in Southern California that are flooded with migrants."

Increasing levels of violence and poverty in Central American countries like Guatemala, Honduras and El Salvador, Johnson said, have propelled entire families to seek safety in the United States. "That itself presents unique challenges," he said, "because our system is really not equipped to deal with a lot of women and children and families. And this administration is seeing that now."

"But a security crisis per se? No. I would not characterize it that way," Johnson said. "I think there is some fear-mongering going on."

In an interview with Intelligence Matters host and CBS News senior national security contributor Michael Morell, Johnson, who also served as general counsel at the Pentagon, said the topic of immigration had been, in his experience, "the most difficult, intractable, emotional, politicized" issue with which he has dealt. He added that its highly-charged complexities make it unlikely for politicians of either party to risk seeking the middle ground.

Last month, the government was partially shut down for a record 35 days amid a failure by lawmakers and the White House to reach a mutually acceptable political solution. Though he had previously threatened a second shutdown, Mr. Trump indicated on Tuesday afternoon that he was close to accepting a bipartisan compromise brokered by congressional leaders late Monday.

Johnson thinks the first one had already taken a toll, saying it had done "a level of damage to our federal government and our security efforts that will last months, if not years, in terms of morale, recruitment, retention, re-enlistment."

And the administration has a litany of other national security priorities to address, he said, including deterring increasingly sophisticated cyber attacks, mitigating terrorist-inspired attacks on U.S. soil, and protecting the integrity of upcoming elections. Boosting security at the southern border is also within the administration's reach, he said, with a few, potentially less contentious, policy choices.

"We have to make a long-term investment in addressing the poverty and violence in Central America," Johnson said. "It has been done before – like the so-called Plan Colombia," he said, referring to a multifaceted aid initiative conceived during the Clinton administration to combat Colombian drug cartels.

"That is not a political quick fix," Johnson said. "And here in Washington, so often people want political quick fixes."

For much more from Michael Morell's conversation with Jeh Johnson, you can listen to the new episode and subscribe to Intelligence Matters here.