Trump's doubt in his own experts makes him reluctant to bomb Iran: Insiders

President Donald Trump's reluctance to pull the final trigger on a bombing campaign in Iran comes in part from skepticism of his own military experts, The Guardian reported on Thursday.

This week, Trump issued a number of direct threats to Iran and announced he would hold off on making a final decision to use military force against the country, allegedly to give them time to agree to dismantle their nuclear program.

But there's a bigger issue, said the report: Trump doesn't believe his own experts' assessment of America's "bunker buster" bombs, which would be necessary to take out Iran's underground nuclear facilities at Fordow.

The president "was told that dropping the GBU-57s, a 13.6-tonne (30,000lb) bomb would effectively eliminate Fordow but he does not appear to be fully convinced, the people said, and has held off authorizing strikes as he also awaits the possibility that the threat of US involvement would lead Iran to talks," noted the report.

The effectiveness of this particular weapon "has been a topic of deep contention at the Pentagon since the start of Trump’s term, according to two defense officials who were briefed that perhaps only a tactical nuclear weapon could be capable of destroying Fordow because of how deeply it is located."

There is no serious consideration of using tactical nuclear weapons; Trump is insistent on only firing the GBU-57s if he can be assured beyond any doubt that it will eliminate Iran's facilities.

Further complicating the problem, the report noted, is that even if the bomb succeeds in destroying the facility, hidden under a mountain, it would only set back Iran's nuclear program, not permanently eliminate it, raising the possibility of future strikes being necessary as well.

All of this comes as Iran itself escalates the rhetoric on their side, warning of "irreparable damage" in the event of a U.S. attack.