WASHINGTON—A group of 40 U.S. Republican members of the Senate and House of Representatives Armed Services Committees urged President Joe Biden to include a 5 percent increase above inflation for defense spending in his proposal for the fiscal 2023 U.S. budget. Biden is expected to announce his budget next week. “As you prepare your fiscal year 2023 budget for submission to Congress, we strongly encourage you to reject the approach you took last year when you proposed to cut defense spending below the rate of inflation,” the lawmakers wrote in the letter, made public on Wednesday. In his first year in office, Biden submitted a budget keeping Department of Defense spending basically flat, as he and many of his fellow Democrats sought to rein in the Department of Defense budget, which has risen to more than $750 billion. “Unprecedented Chinese military modernization has left us behind in key areas in …