be a double-edged sword/weapon

be a double-edged sword

To be something that can be both beneficial and problematic. Going back to school was a double-edged sword for Pam. On the one hand, it widened her career prospects, but, on the other hand, she was in a lot of debt when she graduated.
See also: sword

be a double-edged weapon

To be something that can be both beneficial and problematic. Going back to school was a double-edged weapon for Pam. On the one hand, it widened her career prospects, but, on the other hand, she was in a lot of debt when she graduated.
See also: weapon
Farlex Dictionary of Idioms.

be a double-edged ˈsword/ˈweapon

be something that has both advantages and disadvantages: This new ‘miracle diet’ is a double-edged sword — it’ll make you lose weight fast but you may have some unpleasant side effects.
See also: sword, weapon
Farlex Partner Idioms Dictionary
See also:
  • be a double-edged sword
  • weapon
  • be a double-edged weapon
  • double-edged sword
  • a double-edged sword
  • sword
  • (be) careful what you wish for(, (because) you just might get it)
  • a fine how do you do
  • in the wrong place at the wrong time
  • pull the carpet (out) from under (one's) feet