Washington — President Obama will talk about troop numbers in Afghanistan when he makes a prime-time speech from the White House on Wednesday night. But behind his words will be an acute awareness of what $1.3 trillion in spending on two wars in the past decade has meant at home: a ballooning budget deficit and a soaring national debt at a time when the economy is still struggling to get back on its feet.

As Mr. Obama begins trying to untangle the country from its military and civilian promises in Afghanistan, his critics and allies alike are drawing a direct line between what is not being spent to bolster the sagging economy in America to what is being spent in Afghanistan — $120 billion this year alone.

On Monday, the United States Conference of Mayors made that connection explicitly, saying that American taxes should be paying for bridges in Baltimore and Kansas City, not in Baghdad and Kandahar.

The mayors’ group approved a resolution calling for an early end to the American military role in Afghanistan and Iraq, asking Congress to redirect the billions now being spent on war and reconstruction costs toward urgent domestic needs. The resolution, which noted that local governments cut 28,000 jobs in May alone, was the group’s first venture into foreign policy since it passed a resolution four decades ago calling for an end to the Vietnam War.