Despite the proposed increase for next year, analysts say Pentagon procurement is likely to remain under pressure, and more weapons-buying programmes may be cut, because personnel and healthcare costs are taking up an increasing chunk of the overall Pentagon budget.
Vital national interest
Last week, Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, said he expected Pentagon funding to begin to drop within a couple years because of the country's economic woes.
High unemployment and a record $1.4 trillion deficit are among the toughest domestic challenges facing Obama and could dim the election prospects for his Democratic party in November congressional elections.
Despite that, Obama and his defence secretary, Robert Gates, face a major challenge trimming even a limited number of weapons programmes over the objections of legislators who see them as a source of skilled manufacturing jobs.
After more than two months consulting military leaders, ambassadors and national security advisers in a review of US strategy in Afghanistan, Obama announced last month that he would send an extra 30,000 troops to the war.
The deployment, he said, was in the "vital national interest" of the US, and would create a situation allowing the US to start withdrawing its troops in mid-2011.
He said the additional troops "are the resources that we need to seize the initiative" and bring the eight-year long war to a "successful conclusion".
The increased deployment will increase the US military presence in Afghanistan to around 100,000.