David Welna

As vice president, Bush was deeply knowledgeable about the Iran-Contra scandal, yet insisted he played "no operational role." As president, he pardoned some involved.

The Mexican government, faced with thousands of destitute migrants on their side of the U.S.-Mexico border, is inviting them to apply for jobs in Tijuana.

In Tijuana, thousands of migrants are waiting for their turn for an interview with U.S. immigration officials. Most are camped out in a squalid sports complex that's been turned into a shelter.

On the U.S. side of the border at the San Ysidro port of entry, unarmed active duty troops are assigned to protect Border Patrol officers. Over the weekend, some troops moved from Texas to California.

Asked on Thursday if active duty soldiers being sent to the border with Mexico would fire on migrants who throw rocks, Trump said he hoped not. On Friday, he said soldiers would arrest them instead.

Active duty troops have begun moving to bases in the southwest, preparing for deployment along the U.S.-Mexico border.

Signed by Ronald Reagan and Mikhail Gorbachev in 1987, the Intermediate-Range Nuclear Forces Treaty eliminated an entire class of nuclear weapons. President Trump says he intends to withdraw.

President Trump's declared intention to pull out of the Intermediate Nuclear Forces treaty raises the odds of a new nuclear arms race and the repudiation of arms control as a check against nuclear Armageddon.

In Prague, the year 1968 began with a bold attempt to reform and liberalize its creaking Soviet communist regime from within - "socialism with a human face." Moscow responded harshly, dispatching tanks and hundreds of thousands of troops to crush the movement. 50 years later, authoritarianism is again on the rise in Eastern Europe. NOTE TO STATIONS: The word "bastard" is heard at 4:19.

Polish President Andrzej Duda went to the White House with a big ask of President Trump: a permanent U.S. military base on Polish soil — named Fort Trump.

The Pentagon has just been authorized to make changes to its officer promotion policy that would, among other actions, make it possible to stay on at one's rank rather than face up-or-out promotion peril.

A year ago, President Trump said his original instinct was to pull out of Afghanistan. But he chose to stay. NPR looks at what's changed since then in Afghanistan — and what hasn't.

Hours after President Trump signed into law the annual defense policy bill, he — like his recent predecessors — issued a signing statement challenging the constitutionality of 52 provisions in the bill.

The 2,500-page National Defense Authorization Act, which tells the Pentagon how to spend its budget, is headed to President Trump's desk for signature. A look at its key provisions.

President Trump has claimed his summit with North Korean leader Kim Jong Un has led that nation to begin the process of denuclearization and removed its threat to the United States. A fact check.

The return of possible American GI remains is a hopeful sign from North Korea but Pyongyang continues to produce material needed to produce nuclear weapons.

Defense Secretary Jim Mattis prevailed on a number of policy decisions in the first year of the Trump administration, but his positions have been rejected many times in the second year.

The U.S. and Russia still inspect each other's nuclear arsenals and have sharply curtailed the number of weapons poised to launch. That's thanks to two arms control treaties, which are now at risk.

The U.S. and Russia possess 92 percent of the earth's atomic arsenal. Both recently announced plans to build new nuclear weapons. How will the Trump-Putin summit affect two non-proliferation treaties?

President Trump bitterly criticizes many NATO member countries for not spending more on defense and says they owe the U.S. "massive amounts of money." The reality is more complicated.