The Treaty of Constantinople officially ended the Second Balkan War for the Ottoman Empire, but not, as we have seen, the conviction on the part of an aggrieved public that more war was necessary. And indeed in the months between September 1913 and August 1914, the empire teetered on the brink of war with Greece, which had captured several Aegean islands during the First Balkan War. Throughout these ten months, the foreign ministry worked hard to attract Great Power support for their return. At issue were the islands of Chios and Mytilene, within sight of the Ottoman coast, and the island of Limnos. All three were of critical strategic importance, with Limnos commanding the mouth of the Dardanelles. A war between Greece and the Ottoman Empire contained the potential to draw in the Powers. In the event of war, the Sublime Porte would certainly close the Straits, as it had done briefly after Italy invaded its North African province of Tripoli (Libya) in 1911. Russia could not remain on the sidelines if the war closed the Straits; 50 percent of all its exports, including 90 percent of its grains, shipped through it.