The Pentagon’s five-year nuclear weapons plan calls for requesting at least $167 billion through 2025 — building from the $29 billion sought for next year to $38 billion, according to previously undisclosed figures. The commitment includes research, development, procurement, sustainment and operations. It reflects a major boost to an effort started under President Barack Obama to replace aging nuclear systems, such as Minuteman III missiles and command and control systems. It doesn’t include funding for the Energy Department’s National Nuclear Security Administration, which is requesting $19.8 billion for fiscal 2021, including $15.6 billion for nuclear weapons activities. Congressional Democrats have been generally supportive of increased nuclear weapons spending, but Defense Secretary Mark Esper is likely to be questioned about the size and scope of the five-year plan when he testifies Wednesday before the House Armed Services Committee. Esper is also likely to face bipartisan opposition from the defense-focused committee on President Donald Trump’s plan to shift $3.8 billion from Pentagon programs to his wall on the Mexican border. The Defense Department’s five-year plan on nuclear programs calls for $29 billion for fiscal 2021, $30 billion in 2022 and $33 billion in 2023, before jumping to $37 billion in 2024 and $38 billion in 2025. The plan includes $25 billion for research and procurement — but not support and operations for — the new Columbia-class intercontinental ballistic missile submarine that begins construction this year, $24 billion for improved nuclear command and control and $23 billion for the Air Force’s B-21 bomber. “What you are seeing here is the beginning of a long overdue modernization of the U.S.