Defense Secretary Robert Gates has decided to send an additional 1,400 Marine combat forces to Afghanistan, officials said, in a surprise move ahead of the spring fighting season to try to cement tentative security gains before White House-mandated troop reductions begin in July. The Marine battalion could start arriving on the ground as early as mid-January. The forces would mostly be deployed in the south, around Kandahar, where the U.S. has concentrated troops over the past several months. Commanders in Afghanistan and advocates of the strategy in Washington say temporarily adding front-line forces could help counter an anticipated spring offensive by Taliban militants returning from havens in neighboring Pakistan. Commanders are examining other proposals to temporarily boost the number of combat troops in Afghanistan in addition to the Marines authorized Wednesday. If the plans are approved, the front-line fighting force could be increased in total by as many as 3,000 troops. U.S. commanders in Afghanistan face intense pressure to show sustainable security gains in the first half of 2011. Military officials fear an upswing in attacks by the Taliban in the spring could convince the White House that the Pentagon's war strategy is flawed and that the troop pulloutthe details of which have yet to be ironed outshould be accelerated. President Barack Obama last month said the war strategy was on the right track, but voiced caution about sustaining the gains for the longer-term. "The rationale is to take advantage of the gains we have made over the last several months and apply more pressure on the enemy at a time when he is already under the gun," Pentagon Press Secretary Geoff Morrell said. Some Democrats in Congress are likely to question the decision to boost U.S. combat strength, even temporarily, at a time when the U.S. and its allies are preparing withdrawals, a senior congressional aide said. No congressional approval would be required for the new boost in combat troops, but congressional support is important for Pentagon leaders and commanders who want lawmakers to stand by the strategy. The additional Marine deployment could push the total surge troops in Afghanistan beyond the 30,000 announced by Mr. Obama in December 2009. At the time, Mr. Obama gave Mr. Gates authority to add an extra 10%or 3,000 more troopsto respond to unforeseen contingencies. The Pentagon initially said it intended to use the 10% reserve to rush support units, such as medical or roadside bomb-removal teams, into the war zone if needed. The reserve has, however, been tapped to fill other military needs, including trainers for Afghan security forces. Officials estimate that up to 2,000 of the 3,000 reserve slots have been deployed, but the numbers fluctuate frequently. In addition to the 1,400 Marines being sent, officials are looking at changing the mix of forces in Afghanistan, replacing some support units with additional combat forces. A senior defense official said commanders in Afghanistan have been evaluating which support units are no longer needed. A further boost could come in April and May by introducing new units a few weeks earlier than planned, allowing them to overlap longer with outgoing units. Commanders could also structure new deployments to get frontline troops in place more quickly. Officials said the new deployments wouldn't raise the number of new combat troops above the total authorized by the president. There are now 97,000 American personnel in Afghanistan. It is unclear precisely how many take direct part in combat operations. Top commanders have long sought to reduce the number of logisticians and support staff, and increase the number of frontline troops who leave their bases on missions. The U.S.-led coalition in Afghanistan, known as the International Security Assistance Force, declined to discuss "predecisional operational plans and concepts," said Rear Adm. Vic Beck, an ISAF spokesman. Fighting intensifies every year in Afghanistan when the snow melts in the mountain passages, allowing fighters to flow back into Afghanistan from Pakistan. In a strategy review released in December, the White House said the Taliban's momentum has been arrested in much of Afghanistan, but warned those gains could be reversed, citing the threat posed by militants crossing the border from Pakistan. Senior defense officials hope to build on what they see as recent military gains in clearing Taliban insurgents out of their southern strongholds, with the goal of exhausting the insurgents and forcing at least some of the movement's leaders to the negotiating table. Come June, a senior U.S. official said, commanders should be able to assess the extent to which U.S.-led offensives over the past year have weakened the Taliban, or whether the insurgency is bouncing back. Officials said nearly all the proposed additional troops would be frontline infantrymen who could immediately begin patrolling population centers and remote villages to keep the Taliban at bay. Such a deployment could double U.S. combat capabilities in and around Kandahar, the senior U.S. official said. Preventing Taliban militants from reasserting themselves in the city where the hard-line movement was born is a top American priority. Most of the U.S. surge forces have been deployed to Kandahar and neighboring Helmand province. The troop boost could also buy additional time for training Afghan security forces, which are slated to take over national security from foreign forces by the end of 2014. The plan could meet resistance within Mr. Obama's Democratic Party. Key Democrats, who controlled the House in the last Congress, had pushed Mr. Obama to begin withdrawing troops, and supported the July deadline. Republicans, who now hold a majority in the House, may be more supportive, officials said. Republicans have criticized Mr. Obama's withdrawal deadline, arguing that commanders should get the resources they need to succeed and shouldn't be boxed in by artificial time lines. Anthony Cordesman, a defense analyst at the bipartisan Center for Strategic and International Studies in Washington, said it was unclear what impact, if any, a temporary increase in combat power would have on the overall military campaign as long as the havens in Pakistan remain open to the Taliban. "If the enemy simply chooses to hunker down, ride out, adapt the kinds of tactics that other guerrilla movements have used under acute pressureyou don't win the warall you do is basically create a battle of attrition," he said. Some officials have voiced concerns about the military's ability to maintain control of areas cleared of Taliban, citing the group's ability to replace leaders killed or captured in U.S. Special Operations raids. "As much as we are hammering them in the south and east, their numbers aren't dwindling. They have so many young men who are disenfranchised, who have nothing better to do," the senior U.S. official said. Defense officials in Washington and commanders in southern Afghanistan have offered the White House a more upbeat assessment, pointing to military gains, including routing the Taliban from districts surrounding Kandahar, as well as recent deals with local tribes to keep the Taliban out of their areas. Some American officials believe sustained military pressure could open divisions within the movement or force the group to shift away from a strategy that precludes negotiations with the government of Afghanistan. (WSJ)