From a Washington Post column by David Ignatius headlined “Putin Chokes on the Ukrainian ‘porcupine'”:

As the Ukrainian military grinds forward in a costly summer offensive that hasn’t yet produced a breakthrough, there’s a palpable frustration in Kyiv and in Washington. Maybe it’s a useful moment to recall one of Ukraine’s hidden strengths. Biden administration officials called it the “porcupine strategy.”

Here’s how I paraphrased one White House official’s description of the challenge ahead in January 2022, a month before Russian President Vladimir Putin launched his full-scale attack: “How can the United States and its allies help Ukraine become a porcupine — a prickly, stubborn nation that would be hard for an invading Russian army to digest?”