piracy remains a problem in the Malacca Strait

Malaysia-Brunei: per Letters of Exchange signed in 2009, Malaysia in 2010 ceded two hydrocarbon concession blocks to Brunei; in 2009, the media reported that Brunei had dropped its claims to the Limbang corridor, but Brunei responded that the subject had never been discussed during recent talks between the two countries

Malaysia-China-Philippines-Vietnam: while the 2002 "Declaration on the Conduct of Parties in the South China Sea" has eased tensions over the Spratly Islands, it is not the legally binding "code of conduct" sought by some parties, which is currently being negotiated between China and ASEAN; Malaysia was not party to the March 2005 joint accord among the national oil companies of China, the Philippines, and Vietnam on conducting marine seismic activities in the Spratly Islands

Malaysia-Indonesia: land and maritime negotiations with Indonesia are ongoing, and disputed areas include the controversial Tanjung Datu and Camar Wulan border area in Borneo and the maritime boundary in the Ambalat oil block in the Celebes Sea

Malaysia-Philippines: Philippines retains a dormant claim to the eastern part of Malaysia's Sabah State in northern Borneo

Malaysia-Singapore: disputes continue over deliveries of fresh water to Singapore, Singapore's land reclamation, bridge construction, and maritime boundaries in the Johor and Singapore Straits; in 2008, the International Court of Justice awarded sovereignty of Pedra Branca (Pulau Batu Puteh/Horsburgh Island) to Singapore, and Middle Rocks to Malaysia but did not rule on maritime regimes, boundaries, or disposition of South Ledge

Malaysia-Thailand: in 2008, separatist violence in Thailand's predominantly Muslim southern provinces prompts Malaysia to take measures to close and to monitor the border with Thailand to stem terrorist activities

Cameroon-Central African Republic: Cameroon has deployed military troops to the border to counter intrusions from armed militias and bandits
 
Cameroon-Nigeria: Nigeria recognized Cameroon's sovereignty over the Bakassi Peninsula in 2006 and in completed the transfer of administration in 2013, although there are occasional, mostly local disputes in the area; the the majority of the land boundary was demarcated by 2019 with UN assistance, although there are few disagreements on the precise location of the boundary; the porous border is susceptible to crossings by the Boko Haram and Islamic State of Iraq and ash-Sham - West Africa terrorist groups, both of which operate in Northern Nigeria 

Taiwan-Brunei-China-Malaysia-Philippines-Vietnam: involved in complex dispute over the Spratly Islands in the South China Sea that are thought to have large oil and natural gas reserves, as well as being located amidst prime fishing grounds and busy commercial shipping traffic; the Spratly Islands also are in a strategic position for establishing a military presence to monitor activity in the South China Sea; the 2002 "Declaration on the Conduct of Parties in the South China Sea" has eased tensions but falls short of a legally binding "code of conduct" desired by several of the disputants

Taiwan-China-Philippines: border dispute over the Scarborough Reef in the South China Sea; Scarborough Reef, like the Spratly Islands, is strategically located and is surrounded by abundant fishing grounds; it may also be ripe for oil and natural gas exploration

Taiwan-China-Vietnam: the Paracel Islands are occupied by China but claimed by Taiwan and Vietnam

Taiwan-Japan-China: in 2003, China and Taiwan became more vocal in rejecting both Japan's claims to the uninhabited islands of the Senkaku-shoto (Diaoyu Tai) and Japan's unilaterally declared exclusive economic zone in the East China Sea where all parties engage in hydrocarbon prospecting; Senkaku-shoto is situated near key shipping lanes, rich fishing grounds, and possibly significant oil and natural gas reserves