After 9/11, it seems fair for New York to want to take anti-terrorism into its own hands, even if that duplicates certain federal functions. (I'm not arguing it's effective. Just that it makes sense for the city to not entirely trust the Feds.)
Presumably to coördinate intelligence? (I'm guesing.)
If you don't trust the Feds, your options are to partner or duplicate that capability in house. Partnering seems the cheaper option.
https://en.m.wikipedia.org/wiki/Pegasus_Project_(investigati...
You see things like this and wonder how that money escapes scrutiny when everything else is debated endlessly.
https://www.cbp.gov/travel/preclearance
> Today, CBP has more than 600 officers and agriculture specialists stationed at 15 Preclearance locations in 6 countries: Dublin and Shannon in Ireland; Aruba; Bermuda; Abu Dhabi in the United Arab Emirates; Nassau in the Bahamas; and Calgary, Toronto, Edmonton, Halifax, Montreal, Ottawa, Vancouver, Victoria, and Winnipeg in Canada.
(in the US, even if transiting to another country you are required to clear US customs.)
To my knowledge, the NYPD doesn't patrol outside its borders. The international offices are for coördinating intelligence.
All the rest is just bullshit and security theater (Which NYC is exceedingly good at.)
Notify the Feds.
(Though I guess we can shoot down planes now? [1])
[1] https://nationalpost.com/news/nypd-able-to-shoot-down-planes...