Robert Ball, the former commissioner of Social Security under Kennedy, Johnson, and Nixon, takes issue with the claim that Social Security balance requires benefit cuts. Why? Times have changed. In the Oct. 19 editorial " Mr. Giuliani's No-Tax Pledge," The Post stated: "It's no more responsible for Republicans to rule out tax increases [to strengthen Social Security] than it is for Democrats to insist on no benefit cuts." The Post praised, as a "bipartisan blend," President Ronald Reagan's acceptance of a 1983 fix that included both. I take exception. It's the essence of responsibility, in my view, to insist on no benefit cuts. In 1983, I served on the National Commission on Social Security Reform (better known as the Greenspan Commission) and represented House Speaker Tip O'Neill in negotiations with the White House. What was right in 1983 -- a balanced package of benefit cuts and tax increases as part, roughly half, of the final agreement -- would be wrong today.