Cincinnati ? Sen. John F. Kerry, speaking to the nation’s largest combat veterans organization Wednesday, denounced President Bush’s proposal to bring home troops from Europe and Asia as vague, ill-timed and risky.

In a speech heavily salted with references to his own military service, the Democratic presidential nominee said Bush’s plan would not bolster the United States’ ability to combat terrorism, or relieve the stress on overburdened troops.

“Nobody wants to bring troops home more than those of us who have fought in foreign wars,” Kerry, a former naval lieutenant, told hundreds of VFW members assembled for the group’s annual convention. “But it needs to be done at the right time and in a sensible way,” he added. “This is not that time or that way.”

Kerry’s comments were among his strongest to date in distinguishing himself from Bush on national security — which had emerged as a dominant issue in this year’s presidential race.

The Massachusetts senator, dogged by criticism that he has not been specific enough about how he would handle the turmoil in Iraq differently than the incumbent, pounced on Bush’s troop plan to draw a sharp distinction with the president on a key national defense issue.

“This hastily announced plan raises more doubts about our intentions and our commitment than it provides real answers,” he told the VFW audience at a downtown convention hall.

“For example, why are we unilaterally withdrawing 12,000 troops from the Korean Peninsula at the very time that we are negotiating with North Korea — a country that really has nuclear weapons?”

The debate over national security could be significant for both candidates come Nov. 2. A new Pew Center poll released Wednesday showed that for the first time since the Vietnam War, Americans rank national security as a greater concern than economic issues. Just one-fourth of 2,009 adults polled in July and August rated economic matters as most important.

Democratic presidential nominee Sen. John Kerry, D-Mass., salutes a veteran in the crowd at the 105th Veterans of Foreign Wars National Convention in Cincinnati. Kerry addressed VFW members on Wednesday.