A former New Zealand Prime Minister is drawing similarities between past and present attacks on Iran.

Iranian top general Qasem Soleimani was killed in Iraq on Friday in an air strike ordered by Donald Trump.

Middle Eastern leaders are vowing revenge.

Jim Bolger, who also served as US Ambassador, told Tim Dower is sceptical of Trump's motives.

"It does link back to the President Clinton impeachment trial. President Clinton launched an attack on Iran, and now President Trump is doing the same. It is hard not to draw a conclusion that that's a parallel exercise to divert attention."

He says it's worrying that the most powerful military is under divided leadership.

"None of this is positive in terms of an outlook that you say is the world going in the right direction, is it stable, is it safe, and I'd have to say at the moment it's unstable."

Trump's impeachment trial is currently on hold, as the Senate awaits for the articles of impeachment to be delivered from Congress.