こんなことは許されない。

such (about something or someone close to the speaker (including the speaker), or about ideas expressed by the speaker); like this

thing; matter; incident; occurrence; event; something serious; trouble; crisis; circumstances; situation; state of affairs; work; business; affair; after an inflectable word, creates a noun phrase indicating something the speaker does not feel close to; nominalizing suffix; pretending to ...; playing make-believe ...; alias; aka; nickname; alternative name; also known as

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

to permit; to allow; to approve; to tolerate; to exempt (from fine); to excuse (from); to pardon; to forgive; to release; to let off; to confide in; to give up; to yield