TEHRAN, July 29 — These should be heady days for Iran’s leaders. Hezbollah, widely regarded as its proxy force in Lebanon, continues to rain down rockets on Israel despite 17 days of punishing airstrikes. Hezbollah’s leader is a hero of the Arab world, and Iran is basking in the reflected glory. Yet this capital is unusually tense. Officials, former officials and analysts say that it is too dangerous even to discuss the crisis. In newspapers, the slightest questioning of support for Hezbollah has been attacked as unpatriotic, pro-Zionist and anti-Islamic. As the war in Lebanon grinds on, Iranian officials cannot...