By Natasha Bertrand, Zachary Cohen, Haley Britzky, CNN
(CNN) — As Chairman of the Joint Chiefs Gen. Dan Caine has been drafting military options for potentially striking Iran, a steady stream of top officials from the Army, Navy and Air Force have been quietly summoned directly to his office.
Typically, sensitive military operations are debated in the highly fortified conference room in the Pentagon known as the Tank. But in an administration that is focused on avoiding leaks, Caine — who is also known for his intensive secrecy — worried that assembling the top brass in the Defense Department’s nerve center on very short notice would draw suspicion, according to several sources familiar with the matter.
In those meetings and others at the Pentagon, Caine has been vocal about the potential downsides of launching a major military operation targeting Iran, raising concerns about the scale, complexity and potential for US casualties of such a mission, according to sources familiar with his advice.
Those concerns have not matched the rhetoric coming out of the White House, where President Donald Trump has been bullish on how easily the US military could achieve victory, though the exact dimensions of that success haven’t been defined.
But Caine is determined to avoid what he believes were the mistakes of one of his predecessors, Gen. Mark Milley, and maintain his influence with Trump, according to sources familiar with his thinking.
Milley often clashed directly with Trump during his first term on issues such as deploying the military domestically to quell protests, and sometimes undermined Trump’s inflammatory rhetoric privately to reassure nervous allies and foes.
For Caine, avoiding the Milley approach has meant being more reserved around Trump, and avoiding weighing in too directly on decisions, including what to do in Iran. It’s a tightrope that Caine has been attempting to walk during his year as Trump’s top military adviser – avoid direct conflict with a notoriously mercurial president, while still providing professional military guidance.
Some say Caine hasn’t been assertive enough with Trump. “He’s definitely pulling punches,” a source familiar with Caine’s interactions with Trump said when comparing his White House conversations with his private discussions with military leaders.
Despite any concerns Caine has raised internally, over the last month he has also orchestrated assembling the largest collection of US military hardware assembled in the Middle East since the invasion of Iraq.
This account of Caine’s efforts to navigate his tenure as chairman is based on interviews with 10 current and former officials.
Joint staff spokesperson Joe Holstead told CNN in a statement that Caine “never ‘pulls punches’ when discussing military options which could send our troops into harms way.”
“The role of the Chairman of the Joint Chiefs of Staff and the approach of this Chairman is based on the Chairman’s statutory role to provide military advice to the President, the Secretary of War, and the National Security Council,” he said. “This Chairman fulfills these responsibilities by providing these leaders with a full spectrum of military options, along with precise and thoughtful consideration of the secondary effects, implications and risks associated with each option. He does so confidentially.”
Caine, a former F-16 fighter pilot who spent time as a military liaison to the CIA, rarely divulges his personal opinions on a policy, and his s