strike a blow for/against/at something

strike a blow against (something)

To do something that contributes to something's defeat or downfall. Health officials are hoping that this latest initiative will be able to strike a blow against the obesity epidemic. Reports surfaced today that, if true, will strike a blow against the nascent campaign.
See also: blow, strike

strike a blow for (something)

To do something that helps something or contributes to its success. Relief agencies are desperately hoping that the ceasefire strikes a blow for peace in the region.
See also: blow, strike
Farlex Dictionary of Idioms.

strike a blow for something

COMMON If you strike a blow for something such as a cause or principle, you do something which supports it or makes it more likely to succeed. Her appointment as Prime Minister would strike a blow for women's rights in Poland. Aged 83 and still working, he is also striking a blow for older actors. The ruling struck a blow for free speech. Note: You can also say you strike a blow against something, meaning you succeed in weakening the harmful effect of something. `We have struck a major blow against online fraud,' claims Inspector Ian Woodward.
See also: blow, something, strike
Collins COBUILD Idioms Dictionary, 3rd ed.

strike a blow for (or against)

act in support of (or opposition to)
See also: blow, strike
Farlex Partner Idioms Dictionary

strike a blow for/against/at something

act forcefully in support of/against something (for example a belief, principle or group of people): The protest was a chance to strike a blow for freedom. The new law would strike a blow against racism.
See also: blow, something, strike
Farlex Partner Idioms Dictionary
See also:
  • another nail in the coffin
  • another nail in (one's) coffin
  • coffin
  • a nail in somebody's/something's coffin
  • do something for (someone or something)
  • do something for somebody/something
  • replace
  • be replaced by (someone or something)
  • be replaced with (someone or something)
  • do for (someone or something)