A stapling assembly for stapling tissue, comprising: a staple cartridge, comprising: an annular cartridge body; staple cavities arranged in annular rows in said cartridge body; and staples removably stored in said staple cavities; a firing drive configured to eject said staples from said staple cavities during a firing stroke of said firing drive; an anvil configured to deform said staples; a closure drive (3450 and 2230) configured to move said anvil from an open position to a closed position to compress the tissue against said cartridge body during a closure stroke of said closure drive; and characterized in that the stapling assembly further comprises: a lockout, comprising: a lock element moveable between a locked position and a unlocked position, wherein said lock element is engaged with said firing drive when said lock element is in said locked position, and wherein said lock element is disengaged from said firing drive when said lock element is in said unlocked position; and a cam plate, wherein said closure drive is configured to contact and push said cam plate proximally during said closure stroke, and wherein said cam plate is configured to engage said lock element and displace said lock element from said locked position to said unlocked position, to prevent said firing drive from performing said firing stroke until said closure drive and said anvil have applied a compression force to said cartridge body which exceeds a threshold force. a staple cartridge, comprising: an annular cartridge body; staple cavities arranged in annular rows in said cartridge body; and staples removably stored in said staple cavities; an annular cartridge body; staple cavities arranged in annular rows in said cartridge body; and staples removably stored in said staple cavities; a firing drive configured to eject said staples from said staple cavities during a firing stroke of said firing drive; an anvil configured to deform said staples; a closure drive (3450 and 2230) configured to move said anvil from an open position to a closed position to compress the tissue against said cartridge body during a closure stroke of said closure drive; and characterized in that the stapling assembly further comprises: a lockout, comprising: a lock element moveable between a locked position and a unlocked position, wherein said lock element is engaged with said firing drive when said lock element is in said locked position, and wherein said lock element is disengaged from said firing drive when said lock element is in said unlocked position; and a cam plate, wherein said closure drive is configured to contact and push said cam plate proximally during said closure stroke, and wherein said cam plate is configured to engage said lock element and displace said lock element from said locked position to said unlocked position, to prevent said firing drive from performing said firing stroke until said closure drive and said anvil have applied a compression force to said cartridge body which exceeds a threshold force. a lock element moveable between a locked position and a unlocked position, wherein said lock element is engaged with said firing drive when said lock element is in said locked position, and wherein said lock element is disengaged from said firing drive when said lock element is in said unlocked position; and a cam plate, wherein said closure drive is configured to contact and push said cam plate proximally during said closure stroke, and wherein said cam plate is configured to engage said lock element and displace said lock element from said locked position to said unlocked position, to prevent said firing drive from performing said firing stroke until said closure drive and said anvil have applied a compression force to said cartridge body which exceeds a threshold force.