Police are supposed to rush into a classroom, they just sometimes don't. In many cases, "give them whatever they want" includes a plane ride somewhere, so you r

Police are supposed to rush into a classroom, they just sometimes don't. In many cases, "give them whatever they want" includes a plane ride somewhere, so you really can't just "arrest them on the street". Once you give the hostage takers a plane it's pretty much hijacked, and the US really does not want to do that. If you won't let them leave the area, but want to lead them on for awhile, they would almost certainly figure out and start killing hostages, and then you would have to go in anyway. Giving hostage takers anything more than basic supplies (to string them along for awhile) during negotiations greatly incentivizes hostage taking in your country. Some countries will pay out or allow paying out if the hostage taking takes place in another country (and the forces in that country are not competent or willing enough to pull off a rescue), but it's a bad precedent to do that in your own country.