First, life has to be rewound to Friday, Oct. 26 — the last weekday before Hurricane Sandy crippled and disoriented the New York area. To make that happen, repairs to damaged power grids, transportation networks and housing will grind on for weeks, if not months, at a staggering cost.

But the bigger question is what occurs after that.

Basic restoration leaves everything just as vulnerable to the next monster storm. Hurricane Sandy is now a gauge of the region’s new fragility. Climate change and extreme weather are presenting government — and the public — with some overwhelming choices.

The authorities must not only reopen the Queens-Midtown Tunnel, but also ponder whether to put up sea gates or install inflatable plugs to protect it. Shorted-out circuits in Consolidated Edison’s flooded substation in the East Village stand a foot off the ground in metal sheds. They always seemed impervious to flooding but no longer are.

In New Jersey, the historic Hoboken train terminal had five feet of water sloshing in the waiting room and switches and power substations exposed to salt water. Will it do just to dry them out?