by 1997 crisis. Its leadership considered the armed forces necessary to act as a deterrent, given the country's status as a city-state in a volatile region. It embraced the idea of RMA and enhanced its military technologies. Singapore was the most powerful military in Southeast Asia as of 2004, and there is a continuous political will and funds to do modernize its military. Apart from importing new vehicles into its army, navy and air force, its army also introduced locally built infantry fighting vehicles. During the period of 2009 to 2018, the country allocated a percentage of its GDP to military spending unchanged. It had been the region's largest arms importer, and was ranked top four in Global Militarization Index by Bonn International Center for Conversion since 2007. The country has a well-developed arms industry with the ability to produce locally-made armoured vehicles, artillery and ships, some of which also exported. Singaporean air force is the most capable of long distance action. Singapore has been a participant in the US F-35 programme since 2003. Thailand Thailand had received much military aid from the US in the Vietnam War era. The Communist victory in 1975 and subsequent US withdrawal from the country boosted its military modernization efforts. Domestic factors also played a role: it faced multi-decade long Communist insurgency and infighting in and among its uniformed units vying for more resources. Since the 1990s, the country focused on improving the navy to protect the interest in its Exclusive Economic Zone (EEZ). The purchase of an aircraft carrier Chakri Naruebet indicated its ambition of developing a blue-water capabilities, even though prestige was also a contributing factor. Reform efforts were underway, where all the services were downsized and better-trained. Purchase of artillery, IFVs, tanks, submarines, fighter aircraft and frigates seemed to be its priority. The country often opted for buying second-hand weapon systems or upgrading its existing equipment. The effort was in part due to its worry of losing pace to Malaysia. Military corruption is well documented in Thailand. An average of 15–20% of commissions on arms sales was reported. Domestic political factors also played a role in the allocation of budget when the civilian government repay the navy who did not join the military junta of 1991. Defense ministers often cited lagging behind in number of submarines as the reason for it to have ones of its own. Between 2009 and 2018,