US Chairman of the Joint Chiefs General Dan Caine has become the most dominant advisor to US President Donald Trump on Iran, dating back to June 2025, The Jerusalem Post has learned.
Many other top officials, including US Vice President JD Vance, US Secretary of State Marco Rubio, and US envoys Jared Kushner and Steve Witkoff are also heavily involved, but now that much of the talk has revolved around the potential military scenarios both in terms of America's offensive capacity and limits, as well as in terms of the military costs of an Iranian counterattack, Caine's concerns seem to be getting the most attention.
While Axios and The Wall Street Journal both reported on Caine's role on Tuesday regarding the current Iran situation, the Post can confirm that the US Joint Chiefs chairman had already taken on this central role on Iran as early as the June 2025 Israel-Iran-US War.
According to sources, when key officials wanted to influence Trump and the direction of the June 2025 war, they made special efforts to invest in Caine, even more than some other officials.
For some officials, they experienced this as a shift, to the extent that there was an impression during the Biden administration that more could sometimes be achieved in communication with then CENTCOM chief General Erik Kurilla as opposed to his superior, then Joint Chiefs chairman General C.Q. Brown.
Kurilla and Browns's relative influence was also often covered as such in the media.
However, the Post understands that others viewed Brown as heavily influential, but that he was an unusually modest chairman who did little to cultivate his image with the media.
In any event, sources have indicated to the Post that efforts to influence Trump and the direction of the current situation have also heavily focused on Caine.
IDF Chief of Staff Lt.-Gen. Eyal Zamir, Mossad Director David Barnea, and IDF Intelligence Chief Maj. Gen. Shlomi Binder also visited Washington recently to make their case directly to a variety of officials, but collectively especially to Caine.
On Tuesday, when Trump posted about Caine on Truth Social, he did not deny the influence of Caine so much as he rejected characterizations of the US military chief's views on a potential war with Iran.
With all of that said, current CENTCOM Chief Admiral Brad Cooper, who replaced Kurilla in August 2025, is as influential as ever, in particular as the top commander who has planned the current potential massive American military operations against Iran and will lead them if they come about, the Post understands.
Recent implied criticism from Axios of Cooper as being less influential than Kurilla due to Caine being Trump's primary briefer, whereas Kurilla sometimes directly briefed Biden, can also be viewed as being a low-grade style issue, which mixes in with much larger quirks in how Biden and Trump run their national security decision-making processes.
For example, Biden had a large, powerful, and influential National Security Council run by Jake Sullivan.
In contrast, Trump fired his first national security advisor, Mike Waltz, in May 2025, and proceeded to take apart much of his own NSC, as he directed Rubio to take on the position of national security advisor as somewhat of an afterthought of his already serving as secretary of state.
Cooper might be 'key operational mastermind' in event of war
Next, the Post has learned that as influential as Kurilla was, his direct briefing function was limited.
Moreover, some might even call Cooper the key operational mastermind and point out that if and when there is a war, the world will "see" Cooper's influence play out on the world stage without him having to talk it up; even if he is a commander of a foreign theater, he is not formally a policy advisor per se.
Also, Cooper was sent by the White House to inject fear into the Iranians when he joined Kushner and Witkoff in the first negotiations meeting with Iran earlier in February.
As deputy CENTCOM chief, he also ran significant aspects of US operations in June 2025.
All of that is only in the Iranian arena.
Regarding Gaza, Cooper has been more obviously a critical point man.
He was in Cairo with Kushner and Witkoff to help seal the Israel-Hamas ceasefire.
In Syria, when tensions started to unravel the situation between Syrian ruler Ahmad al-Sharaa and the Kurdish-led Syrian Democratic Forces (SDF), Cooper was sent again by the White House to Syria and Iraq to ensure the SDF could withdraw safely.
Also, he arrived in a helicopter at the front lines to ensure that the most dangerous Iraqi detainees in Syria were transferred in a way that would make certain that they remained in custody.
In addition, some might say that it is also not fair to compare the influence of Caine under Trump, a different president, to Brown's influence under Biden, with the more relevant comparison being the influence of former chairman Mark Milley under Biden.
The idea being that different presidents rely on different advisors for distinct elements of weighing complex issues, such that two presidents' different ways of employing their advisors and commanders are not comparable.
After all of the debates about how much influence one or another adviser will have, all sources also point out that Trump himself will be the final decider.