Mid air refueling works well for the air force.

I've heard it's cheaper (whether this is in terms of risk or dollars I don't know) to send up a dedicated tanker to top of a bunch of large planes that took off with little fuel than it is to make a bunch of large planes take off fully loaded with cargo and fuel.

The problem is that's a whole additional, expensive skill your pilots need.

Fuel from a tanker is an order of magnitude more expensive. It’s worthwhile for the military since they sometimes have a hard time stopping for fuel in the middle of a mission, and like using planes that prioritize the ability to kill people over the ability to go far, but I don’t think it would make much sense for airliners.

they also don't have to be profitable...

Air-to-air refuelling would be way, way, way too dangerous for commercial aviation to even consider.

I disagree, the bigger is the plane, the easier is the refueling

Part of that was due to ETOPS regulations which required twin engine planes to always be within a certain range of a ground airport for emergency landings.

A modern Concorde would almost certainly have an ETOPS rating which would allow for trans-Pacific routes, which is where the true time and fuel efficiency is to be found in supersonic flight.

Uh, Concorde was a quadjet? ETOPS didn't apply (and ETOPS didn't exist when Concorde entered operation).

Whoops, you're right, it was a quadjet. My memory screwed up because both engines on each side are so right next to each other, in my memory they fused into a single engine on each side.

Correct, Concorde had a range of 3900nmi (~7200km, ~4500mi).

LA-Tokyo is ~4700nmi (~8200km), and polar route flights are generally used by planes with a range around or above 7000nmi (~13000km) like the Dreamliner or the A350 XWB

It could stop in Hawaii.

Anchorage, Alaska was a more common stopover between the U.S. West Coast and Japan, Korea, etc. in the days before airliners could easily cross the Pacific in one hop.

ANC is still a major refueling and sorting stop for air cargo -- most all air cargo between China and the mainland U.S. passes through Anchorage. The Anchorage FedEx hub is only passed by Hong Kong and Memphis in terms of volume, and the UPS hub is also one of the largest for that company.

That's counterintuitive when you look at a flat map, but not on a globe.

Here's a flat projection of some great circle routes:

http://www.gcmap.com/mapui?P=SFO-NRT-SIN,SFO-HKG-SIN

Note that the shortest path goes a lot closer to Alaska than it does Hawaii.

Reminds me of something the boss of the company operating a former soviet cargo plane demonstrated. They often figured out how to get the plane somewhere by taking a piece of string cut to fit the flight range of the plane, and placing it on top of a globs to look for suitable airports.

Depends on the destination. Try Sydney, for example.

On most (all?) the round-the-world charters that Concorde did, it had two stopovers on every transpacific leg, one in Honolulu and the other variously in Papeete, Guam, or Fiji (and likely elsewhere, I've not looked exhaustively).

That said, the furtherest north any of those charters landed in the far east was Hong Kong.