Wow there have been several different responses to this question, but not one has mentioned the operator that is designed to do just what you ask, that is the .. operator.

print if (/^Keyword$/../^\s*$/)||0 > 1 and /\S/;

OK, so what does this do. Well the .. operator will return false until the LHS is true. It then returns a true value, this value will initially be 1 but will increment each time, until the RHS becomes true. But it will return true on the line where the RHS is true, so we add the /\S/ check to prevent the output of the last line.

The || 0 is there as for false .. returns "", which -w will complain about.