MoA—China is unlikely to stop buying preferentially priced oil from Iran at least as long as the current trade war with the U.S. continues to intensify. It is also unlikely to join the U.S. ‘coalition’. But it will protect its commercial interest – i.e. its ships that haul goods between Iran and China.
China fears that the U.S. ‘coalition’ will confront its ships for breaking unilateral U.S. sanctions. The British did just that with the Iranian tanker they pirated at Gibraltar. There is also a historic precedence. that demonstrates the necessity to protect Chinese ships against such U.S. schemes: