General Discussion

People can only access classified information if they have the appropriate security clearance AND a need to know the specific information. In addition, there was a tradition where former Presidents continued to have intelligence briefings.

What this action means is that the current administration people starting a new or changed diplomacy challenge can not easily meet with their predecessors who may have faced some of the same people or issues. Even if they philosophically agree on very little, their insight could be useful. Before engaging Putin, both Hillary and Kerry spoke to Kissinger. In Kerry's case, he had a very long history of being on the opposite side.

Trump, in both the current and his first term, essentially rejected not just Obama and Biden administrations but previous Republican administration.