port of Anzali Lagoon put Mohammad Shah in a state of paranoia at the thought of another war. The Russians argued that per the Treaty of Turkmenchay they were free to anchor their ships in the Caspian Sea but neither Mohammad nor Aqasi counted Anzali as part of the sea. To keep the Russian navy away, Mohammad ordered the army of Anzali to shoot at the Russians if they approached. These events led to Nicholas I exchanging letters with Mohammad. In a diplomatic sense, Mohammad allowed the Russian navy to anchor in Anzali. Another source of tension was Russian merchants in Tabriz and Tehran who owed money to Iranians but would not pay them in full. In 1843, Mohammad issued a firman ordering full payments of the debts to prevent fraudulent bankruptcies. During his reign, various matters disturbed Anglo-Iranian relations, the most troublesome of which was Mohammad's campaign to Herat which led the British, for the first time in their relation with Iran, to invade Iran's southern islands in the Persian Gulf. In 1841, Mohammad signed a treaty with the British ambassador under which Britain could reopen their consulates in Tehran, Tabriz and Bushehr but had to withdraw from Kharg Island. This treaty was not ideal for either side; the British did not have the right to reside outside the three cities and their goal was to establish a consulate in Gilan near the Russian border. For Mohammad, the treaty was considered shameful and a surrender to his enemy's demand. After the signing of the agreement, inexpensive British goods entered Iran through the Tabriz-Trabzon trade zone and filled the country's markets, causing the bankruptcy of a number of Iranian businessmen in Tabriz. In 1844, Iranian merchants petitioned to Mohammad to prohibit the importing of European merchandise. In the following year, traders from Kashan implored Mohammad to defend their manufacturers against European merchandise. Both cases were rejected. Mohammad Shah was an avid Francophile and most excited to build diplomatic relations with France in lieu of Britain and Russia. As a child, Mohammad learned French from Madame de la Marininere, a tutor in the court of Abbas Mirza. He denoted French as the diplomatic language of Iran and ensured diplomats and ambassadors from other nations were fluent in French. In 1839, to resume political relations with France, Mohammad sent Mirza Hossein Khan to Paris, where Hossein Khan was brought before King of