VIENNA — Alma Zadic is nervous about standing too close to the row of large windows in her office. Since becoming Austria’s justice minister, the threats have been relentless. “A bullet is reserved for you,” read a recent one. Hours after being sworn in last month, Ms. Zadic was given police protection.

A daughter of Bosnian refugees and member of the progressive Green Party, Ms. Zadic went into politics three years ago with a clear goal: to fight an ascendant far right.

Now, she is charged with defending policies that were codesigned by the far right in previous years to effectively keep people like her parents out of the country.

That, in a nutshell, is the moral dilemma facing Austria’s liberal pro-refugee Greens in joining forces with the conservatives of Chancellor Sebastian Kurz. The Greens have replaced the far-right Freedom Party as junior partners in government and get to put climate change on the political agenda. But they are also becoming complicit in Mr. Kurz’s hard-right immigration policy.