List of Articles International System Open Access Article Abstract Page Full-Text 1 - The Role of Obama and Trump's Foreign Policy on International System Structure Yosef Shahmohammadi Hassan Khodaverdi Mohammad Reza Dehshiri Open Access Article Abstract Page Full-Text 2 - The Decline of the Structural Power of the United States of America and the Consequent Effects on the Relations Between Saudi Arabia and the Islamic Republic of Iran (2001-2020) Sajjad Hasani Hassan Khodaverdi Garineh Keshishyan Siraki Open Access Article Abstract Page Full-Text 3 - Investigating Security Challenges in the Contemporary International System with Emphasis on Economic, Human Rights and Environmental Components Khademali Tahzibi Reza Simbar Garineh Keshishyan Hassan Khodaverdi Open Access Article Abstract Page Full-Text 4 - Ukraine crisis: Trends and Perspectives Majid Divsalar Open Access Article Abstract Page Full-Text 5 - The Impact of US Strategy on Identity Conflicts between the Islamic Republic of Iran and the European Union Farzaneh Rahmati Mohammadreza Dehshiri Open Access Article Abstract Page Full-Text 6 - Explanation of Theoretical Basics of Analysis of the World Order Alireza Rezaei