bilateral naval maneuvers held in the Peter the Great Bay of the Sea of Japan. To date, Joint Sea 2013 was the largest naval drill yet undertaken by the People's Liberation Army Navy with a foreign navy. On 2 April 2015, during the violent aftermath of a coup d'état in Yemen and amid an international bombing campaign, the PLAN helped ten countries get their citizens out of Yemen safely, evacuating them aboard a missile frigate from the besieged port city of Aden. The operation was described by Reuters as "the first time that China's military has helped other countries evacuate their people during an international crisis". China's participation in international maritime exercises is also increasing. In RIMPAC 2014, China was invited to send ships from their People's Liberation Army Navy; marking not only the first time China participated in a RIMPAC exercise but also the first time China participated in a large-scale United States-led naval drill. On 9 June 2014, China confirmed it would be sending four ships to the exercise, a destroyer, frigate, supply ship, & hospital ship. In April 2016, the People's Republic of China was also invited to RIMPAC 2016 despite the tension in South China Sea. PRC military expert Yin Zhuo said that due to present weaknesses in the PLAN's ability to replenish their ships at sea, their future aircraft carriers will be forced to operate in pairs. In a TV interview, Zhang Zhaozhong suggest otherwise, saying China is "unlikely to put all her eggs in one basket" and that the navy will likely rotate between carriers rather than deploy them all at once. The PLAN continued its expansion into the 2020s, increasing its operational capacity, commissioning new ships, and constructing naval facilities. Observers note that the PLAN's ongoing modernization is intended to build up the Chinese surface fleet and fix existing issues that limit the capability of the PLAN. Observers have noted that the PLAN's expansion will allow it to project Chinese power in the South China Sea and allow for the navy to counter the USN's operations in Asia. Chinese naval capability increased substantially in the 2010s and 2020s. According to the US-based think tank RAND Corporation, PLAN enjoyed major advantages in terms of naval technologies, missiles, and tonnage against regional rivals such as Taiwan, Japan, Vietnam, the Philippines, and India. And analysts believe China will further improve its power projection capability to challenge