Federal Reserve officials participating in a “war game” exercise this year came to a disturbing conclusion: Six years after the financial crisis ended, the central bank remained ill-equipped to quell the kind of dangerous asset bubbles that destabilized the savings-and-loan industry during the late 1980s, tech stocks in the 1990s and housing in the mid-2000s.

The five officials—gathered at a conference table in Charlotte, N. C.—had to determine if hypothetical booms in commercial real estate and corporate borrowing risked...