A Republican clash over Israel is spilling into public view, a bad sign for party unity on foreign policy.

• JD Vance said something about Israel that drew a furious response from Randy Fine.
• Fine pushed back hard, insisting the U.S. did not create Israel and barely funds it.
• He told Vance to "go back and learn his history," a sharp personal jab between allies.
• The fight shows growing tension among Republicans over how tightly to tie the U.S. to Israel.

Outlook: Expect more open infighting on the right over America's role in backing Israel.