establishment of formal diplomatic relations between Israel and the United Arab Emirates, a deal signaling deeper cooperation between the Jewish state and Gulf Arabs to counter Tehran as it vies for regional influence. In a nationally televised speech Saturday, Iran’s president, Hassan Rouhani, said, “We warn the Emirates: Don’t open the region for the Zionist regime to step in.” If the agreement leads to expanded Israeli influence in the region, Mr. Rouhani said, “Things will change, and they will be dealt with in a different way.”