Intelligence Sharing, Not.

From today's Wall St Journal, we have "Group Finds Intelligence Gap Persists". The bipartisan Markle Foundation Task Force on National Security in the Information Age says "Today we are still vulnerable to attack because- as on 9/11- we are still not able to connect the dots."
Not surprising. Intelligence agencies fear that intelligence sharing leads to leaks to the press which can reveal the names of agents, getting them killed, or let the enemy know his codes have been cracked, leading him to change the codes. You'd have to be really stupid to share anything with CIA, since everything CIA knows goes right to the New York Times. Any rational intelligence agency is going to resist exposing its secrets to other agencies for fear the other agency will blow the secret. There is a saying "Three people can keep a secret only if two of them are dead."
It's unrealistic to expect professional intelligence agencies to share anything with anyone. They have learned you keep secrets by not telling them, to anyone.
For more intelligence sharing, you have to do what the Russians did, put all intelligence gathering into the same organization, KGB. That works, but it's scary. We divvy up intelligence work between CIA, FBI, NSA, Defense Dept, State Dept, and God knows who else, to keep the intelligence agencies small and weak, so they can't take over the country.
Best we can hope for, given the fragmentation of US intelligence system, is to get them to share lists of bad guys. Failure to do this was a big part of 9/11. State dept passport and visa people will let most applicants into the country unless the other intelligence agencies give them lists of bad guys to keep out.