Map below shows current Amtrak rail stops, from Washington DC to Boston.
Note that the DC-NYC run spans six political divisions, DC, Maryland, Delaware, Pennsylvania, New Jersey, and New York, each with it's own political representatives subject to pressures by various interest groups, a situation not present in Japan.
Eight stops between start and end points. With TSA governing entry points to the system, five minutes at each stop, boarding and unboarding, eats up the entire 40 minutes Mr. Abe envisions for transit.
Highly unlikely that the five minutes can be reduced as our inhomogeneous population cannot yet be herded and pushed into trains in the manner in which the Japanese are accustomed.
Various high speed rail solutions have been tried over the years for the BostonWashington corridrightirst the Metroliner, then the current Accela, none of which achieved the hyped initial proposals. All attempts to limit stops have failed to deliver on the promises. In fact, additional suburban stops have been added to service the urban fleeing suburban jobs market. Few inner city workers use the trains to commute.
Unmentioned are the burdens Unions and minority set aside contracts impose on the implementation of any rail system.
The Eastern DC-NYC air shuttle achieved the approximate 40 min flight time, airport to airport at a reasonable cost, although at double or so the train fare at the time. It remains to be seen what the eventual MagLev real final cost would be and how that would translate to ticket prices, barring Federal subsidies, that old socialist porkbarrel money laundering scheme.
Finally, does anyone detect the smell of Elon Musk behind the curtains. This one is right up his alley