Former NATO chief Adm. (ret.) James Stavridis has it exactly right: The world has no choice but to open “a new front in the war . . . over the next few weeks” to stave off a global food crisis. This doesn’t require getting involved in the fighting, but it does mean staring down Vladimir Putin.

Russia occupies or blocks all of Ukraine’s Black Sea ports, preventing the export of a tenth of the world’s grain supply. If the harvest can’t get out starting late this month, much of Africa and the Middle East, in particular, face at least huge price hikes and perhaps starvation.

And, as Gen. Christopher Cavoli explained during his confirmation hearing for Stavrides’ old NATO job, that would trigger unrest and even fuel terrorism, as ISIS and its ilk “feed on weak governance and food insecurity and corruption and poverty.” It could also trigger another wave of millions rushing to Europe.

The clear answer is a NATO (mainly US) humanitarian naval operation to escort grain freighters out of the war zone. It’s all international waters, so Putin has no legal cause for complaint, though he’ll surely huff and puff.

Kremlin threats have already led President Joe Biden to deny Ukraine fighter jets the Poles want to send, and to severely limit what longer-range missiles Washington will provide. That’s allowed Putin to level and occupy roughly a fifth of Ukraine.

US Joint Chiefs of Staff head Gen. Mark Milley calls action to break the blockade “a high-risk military operation,” but he’s reliably wrong.

This isn’t about helping stop Russia’s war of conquest; it’s about keeping the world’s most vulnerable fed. Too much is at stake for Biden to blink yet again.