Fear Be Damned: This Is the Time to Invest

FORTUNE -- Never underestimate the impulse for Wall Street market strategists and pundits to spin an outbreak of sudden fear into a durable trend, with a sensible-sounding narrative to back it up. So it is today with the sharp selloff in emerging market stocks and bonds. For champions of U.S. equities, indeed, the panic overseas seems a timely gift. Talk up the chill in China's growth machine -- now throw in some turmoil in Turkey -- and suddenly the notion of paying a fat premium for U.S. stocks seems downright reasonable. After all, if America is once again the bastion of safety, then its stocks should command far more handsome valuations than shares in the unstable developing world, no?