Defense Secretary Robert Gates's decision to take a pass, at least for now, on a proposal to send marines to Afghanistan leaves the future security of that country an open question.

Secretary Gates appears to have rejected the proposal by Gen. James Conway, the Marine commandant, in part because Gates wants other nations to contribute more personnel to the NATO-led force in Afghanistan. Many say security there has deteriorated in the past year.

Political considerations at home may also be a factor in the decision. As security improves in Iraq, a move to send more American troops back to Afghanistan could be grist for Democrats in an election year, analysts say. US commanders in Iraq are also wary of redeploying troops from Iraq too quickly.

Gates seems to have heeded Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, who opposed the plan.

"There is a determination that right now the timing is not right to provide additional Marine forces to Afghanistan," General Conway said Wednesday.

Conway had lobbied for a major combat role in Afghanistan that could have included as many as 15,000 marines to help an international force fight a resurgent Taliban. He indicated that his proposal might be revisited in the future.