Cairo, alBawaba - A political scientist said on Monday that there was no significant difference behind Islamic State (IS, also widely known as ISIS) choice to move its terrorist activities to Yemen. Professor of political science at Cairo University 'Hassan Salama' explained in a statement to Al-Bawaba News Portal that the occurrence of a terrorist organization and the disappearance of another does not make much difference, because both speak in the same way and commit the same acts, adding that ISIS' move to Yemen was expected. He pointed to Al-Bawaba that IS' terrorist activities may increase in Yemen, as a result of the rising pressure being exerted on the terrorist organization in the battlefields, especially in Syria, Iraq and Libya. The political science professor explained that IS' move to Yemen is due to several reasons, including, the geographic location and the ability to seize important waterway, which will most probably cause great concern to the Gulf States, thus the situation is completely different than that of Syria, Iraq and Libya. Salama revealed that IS' move to Yemen threatens the safety and security of maritime movements and trade, which form different concerns that drain a lot of money from countries that feel threatened by ISIS' danger and are compelled to act in order to eliminate the threat. He stressed that ISIS will not retreat from Yemen unless it is replaced by another terrorist organization that carries out the demands of the major powers, especially the United States, adding that it was time for al-Qaeda to disappear in order for the era of IS to begin.