Johor holds a very unique position in the Malaysia-Singapore relations. Although it has been part of the Federation of Malaysia, the present day mainland Johor has very special historical, political, social, and cultural ties with Singapore. Every day, nearly 80,000 Malaysians commute to Singapore to work. Malaysians who reside in Johor, in fact, have been the major source of workers for Singapore's industrialization for decades. Hence, any political tensions between Malaysia-Singapore could not run away from discussing the involvement of Johor. The causeway, one of the two bridges that link Johor to Singapore, for instance, was the site of Malaysian Non-Governmental Organizations’ (NGOs) protest against Chaim Herzog's visit to Singapore in November 1986. The demonstrators had threatened to cut the water supply from Johor to Singapore and created anti-Singapore sentiments across the country. Johor again became the centre of political spats in March 1997 when the then Senior Minister Lee Kuan Yew made controversial remarks in his affidavit over the defamation suits against a Singaporean opposition politician Tan Liang Hong, who fled and resided in Johor. Senior Minister Lee called Johor a place for “notorious for shootings, muggings, and car-jacking” which sparked a diplomatic uproar. Lee later apologized and also retracted the remarks in the affidavit and blamed press reports for the misunderstanding.

As the southernmost state of peninsular Malaysia and the most immediate neighbour to Singapore, Johor is inevitably affected by and caught up in any political tension existing between the two neighbouring countries. Issues of water supply, the use of Malaysian airspace by the Republic of Singapore Air Force (RSAF), the Pulau Batu Putih/Pedra Branca disputes, the design of a new bridge to replace the 100-year old causeway, and Singapore's land reclamation projects, without doubt, have major socio-political and economic implications, either in a positive or negative way, for Johor.

The government of Johor is indeed represented in the bilateral negotiations between Malaysia and Singapore. Nonetheless, it does not have direct negotiation power, as will be discussed later in the chapter, due to the constitutional barrier under the federal-state concept. Johor is also part of a tripartite, sub-regional economic integration under the Singapore-Johor-Riau (Indonesia) or SIJORI growth triangle concept. The idea is premised on mutual cooperation whereby land-scarce Singapore's requirement for low, value-added and labour-intensive industries that can only be offered by neighbouring countries.