Don't let the rally in the stock and bond markets fool you. Many Americans are still hurtling towards a retirement disaster. Few realize it. Even many of those running the big pension funds don't know.

That's the conclusion of John West and Rob Arnott at Research Affiliates, an investment management firm, in Newport Beach, Calif. In their latest report, "Hope Is Not A Strategy," they have some numbers to back it up.

"I...