For months, the left has attacked President Donald Trump’s executive order suspending travel from several terror-prone countries. Sadly, the Manchester terror attack shows why his order was justified — even beyond its original, expansive form.

The terrorist, Salman Abedi, was a British citizen, born to Libyan refugees. That alone is not a reason for him to have aroused suspicion. But his travel to and from two terror-prone countries — Syria and Libya– should have been.

The UK Telegraph notes (emphasis added):

Suicide bomber Salman Abedi is believed to have travelled to Syria and become radicalised before returning to the UK to cause carnage at a gig in the city where he was born.

The son of Libyan parents, who reportedly fled their native country and sought refuge in the UK, he is thought to have come back to Britain from Libya just days before the massacre.

One of the most common criticisms of Trump’s original executive order was that it was too broad, because it applied to people who had already had some legal right to travel or immigrate to the United States. The Abedi example suggests that the executive order may not have gone far enough: it only applied to non-U.S. citizens.

(The later version of the executive order exempted permanent residents and dual citizens, among other categories.)

The federal judges who stopped the executive order, and who have blocked its successor, have thrown away the traditional deference by the judiciary to the executive on matters of national security. (A federal judge in Boston allowed Trump’s order to stand because it “decline[d] to encroach” on the president’s constitutional role and legal authority.) Instead, they have purported to read discriminatory intent from cherry-picked campaign statements.

There is an active terrorist threat in Syria, Libya, and elsewhere, and the President of the United States wants to stop it from reaching our shores, as it has already reached Britain and Europe. The President also has access to information the courts do not and should not have.

The executive order is a legal and constitutional exercise of presidential powers. Indeed, any president who did not consider such measures would be neglecting his duties.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named one of the “most influential” people in news media in 2016. He is the co-author of How Trump Won: The Inside Story of a Revolution, is available from Regnery. Follow him on Twitter at @joelpollak.