evidence: Malaysia, a federal constitutional monarchy in Southeast Asia, gained independence from the British in 1957 and the Federation of Malaysia, comprising Malaysia, Sarawak, and Singapore, was officially declared in 1963. Singapore left this federation in 1965, by mutual agreement, after widespread ethnic and political tensions. The two nations have often had prickly relations marked by disputes over deliveries of freshwater to Singapore, land reclamation works, bridge construction, and maritime boundaries in the Johor and Singapore Straits. In a 2008 dispute over territory in the Singapore Strait, the International Court of Justice awarded the Pedra Branca Islands to Singapore and the Middle Rocks to Malaysia. However, it did not rule on the disputed South ledge. In 2017, Malaysia applied for ownership of the South Ledge. The two countries have recently engaged in aggressive maritime activity that seeks to extend their territorial waters, especially over the ports of Johor Bahru and Tuas. [...] Another source of concern was an existing arrangement that allows Singapore’s air traffic controllers to manage airspace over southern Johor. PM Mahathir had said that Malaysia intended to take control of the airspace in stages, beginning in 2019. Singapore is a developed air-traffic hub and Malaysia intends to maintain its control over the strategic airspace. However, both countries have included as a part of the de-escalation measures a suspension of Malaysia’s permanent Restricted Area (RA) designation over Johor’s southern Pasir Gudang and withdrawal of Singaporean Instrument Landing System (ILS) procedures at Seletar Airport, allowing Malaysian carrier Firefly to use the airport.