Bush-era Ziocon and former UN ambassador, John Bolton, is now Trump's National Security Adviser.
We already know what he wants to do:
"Just 8 months ago, at a Paris gathering, Bolton told members of the Iranian exile group, known as the Mujahedeen Khalq, MEK, or People's Mujahedeen, that the Trump administration should embrace their goal of immediate regime change in Iran and recognize their group as a 'viable' alternative. 'The outcome of the president's policy review should be to determine that the Ayatollah Khomeini's 1979 revolution will not last until its 40th birthday,' Bolton said. (The 40th of the Iranian revolution will be on February 11, 2019.) 'The declared policy of the United States should be the overthrow of the mullahs' regime in Tehran,' Bolton added. 'The behavior and the objectives of the regime are not going to change and, therefore, the only solution is to change the regime itself.' As the Iranian expatriate journalist Bahman Kalbasi noted, Bolton concluded his address to the exiles with a rousing promise: 'And that's why, before 2019, we here will celebrate in Tehran!'" (Here's John Bolton promising regime change in Iran by the end of 2018, Robert Mackey, theintercept.com, 24/3/18)
Now check out Bolton's cv to find out why he wants to do an Iraq on Iran:
"Before joining the Bush II administration, Bolton had been Senior Vice President for Public Policy Research at the American Enterprise Institute and a member of the Project for the New American Century and the Jewish Institute for National Security Affairs (JINSA). Bolton had been a regular contributor to William Kristol's Weekly Standard. In December 2005, after becoming US Ambassador to the United Nations, Bolton would be the keynote speaker at the right-wing Zionist Organization of America's Louis Brandeis Award Dinner, where he received the ZOA's Defender of Israel award." (The Transparent Cabal: The Neoconservative Agenda, War in the Middle East, and the National Interest of Israel*, 2008, p 123)
[*Required reading; see also my 7/1/16 post Tom Switzer Channels Oded Yinon in the Herald.]