Question comments: "There are claims in some of the answers and comments in the question
Acceptable evidence would be official speeches or government statements/reports justifying the shift in mother tongue education policy from the 1980's. Ex post facto policy justifications are not acceptable."
tl;dr - hardly
Long version:
To answer this question, we need to look at documents from the time of the launch of the Speak Mandarin Campaign.
The Speak Mandarin Campaign was launched on 7 September 1979 (Speak Mandarin Campaign).
According to the Straits Times, in August 1979, Parliamentary Secretary (Culture) Dr Ow Chin Hock gave two reasons for the Speak Mandarin Campaign (Goal tor common language among Chinese):
- So Chinese in Singapore could communicate with Chinese speakers in other countries. There was also this semi-cryptic line in the report: "the change of political and economic situations in Asia will enhance the importance of Mandarin". This probably referred to the rise of China, but the cagey nature of the language is puzzling.
- So students wouldn't be as burdened in "learning the two languages". Presumably this referred to both Mandarin and a student's "dialect" (i.e. non-Mandarin Chinese language). This being Singapore, I doubt that letting students learn less was a priority - especially in the 1970s. So I am inclined to think that this was just an excuse.
Another reason given in this article was Mandarin being "conducive to the soul of the nation and the people". This mystical line baffles me.
Yet another justification given for the Speak Mandarin Campaign was "to preserve the fine cultural tradition of the Chinese" (Panel set up to promote Mandarin).
Oddly enough, there are not many mentions in the Hansard (aka the Official Reports - Parliamentary Debates - Page on parliament.gov.sg). I only got 5 hits for "Speak Mandarin" for the 4th Parliament (1977-1980). So it seems the Speak Mandarin Campaign was not a political measure so much as an administrative one.
Above all, what is evident is that the Speak Mandarin Campaign cannot be looked at in isolation.
The Speak Mandarin Campaign was implemented because of the lukewarm success of the Bilingual Policy, as summarised in 1979's Report on the Ministry of Education 1978 (aka the Goh Report; summary: http://eresources.nlb.gov
Young Chinese Singaporeans were not effectively bilingual, because they did not speak either English or Mandarin (the 2 languages they were supposed to be bilingual in) at home. Furthermore, with industrialisation as well as the rise of English-medium schools, "mother tongues" like Mandarin were becoming less prestigious. The solution was to promote the use of Mandarin.
The question we need to answer, then, is if there is evidence that the Bilingual Policy was promulgated in anticipation of China's later rise as an economic power.
According to the Goh Report, the objective of the bilingual policy was, according to MOE at the time, "to build a cohesive multi-racial society" (page 51/112 of the report). Unfortunately there isn't any indication of what this might mean or entail. And the Handard of the first Parliament (during which the Bilingual Policy was promulgated) doesn't talk about its aims.
Fortunately Patrick Ng (http://www.apu.ac.jp/rca
In short, improving links with China were an afterthought (at best) in the promulgation of the Speak Mandarin Policy.