Here is more from Politico:
The Pentagon has suspended participation in all think tank and research events until further notice, according to an email sent Thursday to staff and obtained by POLITICO, a major shift in engagement from the country’s largest federal agency.
The decision comes a week after the Defense Department pulled out of the high-profile Aspen Security Forum citing “the evil of globalism” and indicating the event did not align with the Trump administration’s defense policies.
The Pentagon’s public affairs office is also reviewing the agency’s participation in other top security conferences, according to the email. It specifically banned attendance at the Halifax International Security Forum, which takes place in Nova Scotia each winter and where the Pentagon chief is usually a top guest. It was not immediately clear why that forum had been singled out.
The move would sideline the Pentagon from national security dialogues that it has used for decades to advance its policy and explain the department’s rationale. Former Defense Secretaries Jim Mattis, Mark Esper and Lloyd Austin have also used think tank events, such as the International Institute for Strategic Studies’ Shangri-La Dialogue and the Reagan National Defense Forum, to give major policy speeches and hold sideline meetings with both allies and adversaries.
The Pentagon’s public affairs, general counsel and policy teams will review all requests for participation at events and will ask for officials’ remarks and talking points in advance, according to the email. The directive, which took effect Tuesday, applies to all DOD military officers, civil servants and senior enlisted leaders. The Pentagon’s public affairs team must approve any future events.
The Pentagon also funds numerous think tanks, including the RAND Corporation, Center for Strategic and International Studies (CSIS), Atlantic Council, Brookings Institution, and Center for a New American Security (CNAS).
Here is a piece from The Atlantic entitled "The Pentagon Against the Think Tanks."