Eight days after the U.S. military dropped its largest ever conventional bomb on suspected Islamic State fighters in eastern Afghanistan, Taliban militants breached an army base in the north of the country and killed scores of local soldiers.

To Afghan and other critics of U.S. President Donald Trump's apparent indecision over how to win a seemingly intractable war, Friday's assault — the worse of its kind since the Taliban were ousted in 2001 — was evidence he is getting it wrong.

"The biggest threat to the security and stability of this country is the Taliban insurgents, not Daesh forces," said Mirwais Yasini, an influential Afghan member of parliament from Nangarhar province, using an Arabic term for Islamic State.