Breaking with tradition, the U.S. Army has submitted its revised 2017 and new 2018 lists of unfunded priorities ahead of the next budget submission. Both lists include offensive and defensive missile systems as part of an effort to modernize aging systems considered critical for U.S. military operations. The 2017 list includes a $1.3 billion request to further fund short-range air defense (SHORAD) systems and to procure more PAC-3 missiles and upgrades to the existing Patriot missile systems. The 2018 wish list requests $1.5 billion, much of which would be spent on the Army Tactical Missile System (ATACMS) life-extension program, a stop-gap measure which would keep the missile in service until a replacement can be fielded. An additional $1 billion is requested in 2018 for Patriot missile and radar upgrades in Europe.