Kinda rubbish. Almost all of the terrorists that have been a problem are Sunni. Iran is Shia, the exact enemy of the Sunni. Kind of a severe shortage of Shia terrorists going around the world blowing stuff up. Al Qaeda, ISIS, the Taliban, all those are the enemies of Iran too.
There was one document about the threat of Iran from the DoD I read a while back, the main points were "Iran 5 years from an ICBM" (much longer than 5 years ago) which was basically sci-fi, they pointed out that Iran's military is entirely geared for defense, they basically don't have any force-project capabilities or doctrines. And actually, on a regional scale, they're not actually a large spender on the military. It's basically a lie that Iran is causing some sort of arms race. Their total defense budget is $15 billion, compared to the $700 billion of the USA, and it's actually dropped over the last 10 years. Meanwhile the USA is encouraging a massive arms build up in Saudi Arabia, a nation much more plausibly connected with international terrorism.
The real actual threat mentioned in the report was that Iran would conduct diplomacy with their neighbors. That's the thing the USA really cares about. The thing about the ICBMs at the start of the document was for show, and made the point that with "sufficient" international support, Iran could get an ICBM any day. In other words, the regional diplomacy was the real threat in the report, but they had to have the big military scary thing at the start so they basically said that Iran could get an ICBM "any day now" ... if other people built one for them. It's basically bullshit.