Why are we only seeing these documents six years after the bin Laden raid? The answer is simple and a disgraceful stain on Obama's administration. He feared that if voters knew the truth about how Iran worked to support al Qaeda after 9/11, they would oppose his nuclear deal with Ayatollah Ali Khamenei.

President Trump deserves credit for letting Americans see the truth, and he must continue acting to constrain Iran's international predations. Two incidents from last Saturday underscore the reasons why.

First was the ballistic missile attack on Riyadh, conducted by Iranian-backed Houthi rebels in Yemen. Iran almost certainly had an intimate role in its deployment. We can say this confidently, because Houthi commanders would not risk jeopardizing Iran's longstanding command and control, logistics and training support by taking such aggressive action against the Saudi capital without Iran's blessing.

Then there was Lebanese Prime Minister Saad Hariri's decision to resign, claiming Iran and its ally, Hezbollah, were plotting to assassinate him. Hariri's position had become increasingly tenuous in recent months, as Hezbollah assumed greater influence over the Lebanese armed forces and senior political figures such as President Michel Aoun. Hariri evidently concluded that his resistance to Hezbollah interests had become life-threatening. It's a justifiable concern; in 2005, Hariri's father was assassinated when Iran's puppets, Syrian President Bashar Assad and Hezbollah, blew up his motorcade.

Saturday's events reveal escalating Iranian efforts to weaken American allies. They deserve a proportionate U.S. response.

First, in Saudi Arabia, the U.S. should support Crown Prince Mohammed bin Salman's attempts to remake his nation as a westward-looking, opportunity-driven society.

Second, in Lebanon, the U.S. should work to ensure that only military officers independent of Hezbollah receive American aid. We should also sanction officers who kneel to Hezbollah's flag.

Third, recognizing that Iran may believe America is distracted by North Korea, Trump should consider deploying a carrier strike group to the Persian Gulf.

As it confronts these latest challenges, the Trump administration must be aware of history. Following the 2011 Iranian bomb plot against a Saudi ambassador and other diners in a Washington restaurant, the Obama administration responded with characteristically limp inaction. In 2013, Jim Mattis, who is now defense secretary, explained the risks of Obama's appeasement.

The "[Iranian revolutionary guards] are like children balancing lightbulbs full of nitroglycerin, you get the picture ... One of these days they're going to drop one and it's going to knock out the London stock exchange or Wall Street, because we never drew a line and said you won't do it. Now it's very important we stand up as Americans and say this is what I stand for, but it's also very important once in a while that we say this is absolutely what we won't tolerate."

Whether plotting against America or our allies, Iran never encountered the pushback that we so urgently needed to administer. Now, as Iran now rolls the dice again, the Trump administration must not make the same mistakes as its predecessor.