SINCE its formation in 2010, the National Planning Commission (NPC) has offered a frank diagnosis of the challenges that confront South Africa. It has championed constitutional democracy, an effective state and a policy process based on reason. Through its National Development Plan (NDP), it has sketched a route map towards a broadly social democratic future.

The African National Congress’s (ANC’s) apparent embrace of the plan in Mangaung therefore has a powerful symbolic significance. So too does the fact that Cyril Ramaphosa, deputy chairman of the commission, was elected deputy president of the ANC.

The Cabinet adopted the National Development Plan last year as a basis for future government planning. The plan is already being built into the annual budget cycle, and "integrated implementation plans" are under development by directors-general.

Changes since Mangaung in the composition of ANC national executive committee subcommittees confirm a political shift. The economic transformation committee is now packed with leaders strongly committed to the plan, including Pravin Gordhan, Tito Mboweni, Joel Netshitenzhe and Max Sisulu. The rise of the pro-commission wing of the leadership is signalled by the multiple responsibilities of key modernisers: Gordhan, for example, sits on five ANC national executive subcommittees and Sisulu on six. Ramaphosa’s rise was therefore not an expression of individual opportunism, but rather one manifestation of a wider change in the ANC political landscape.

A further advance of modernising sentiment is not guaranteed. The plan asserts the authority of scientific knowledge and proposes a rational state bureaucracy. Such initiatives allow it to be construed by its enemies as a westernising or racial project. Any attempt to persuade politicians and officials to think in the long term and work together confronts complex counter-incentives.

While the National Development Plan has been adopted by the Cabinet, so too have modernising frameworks from the left, such as the New Growth Path and iterations of the Industrial Policy Action Plan. In the week before Mangaung, South African Communist Party deputy general secretary Jeremy Cronin indicated the National Development Plan was "compatible" in the end with these somewhat more statist instruments. But real work has yet to be done to realise whatever potential convergence exists.

Zuma, an emperor of few clothes, is happy to deploy the National Development Plan fig leaf to cover his embarrassment at the World Economic Forum. He may be less willing or able to give the plan the political protection it will need. The test will come when hard decisions are taken. In energy policy, an amalgam of foreign policy gurus, parastatal barons, securocrats, and industrial policy enthusiasts are keen to buy six nuclear power plants from a Franco-Chinese consortium at a cost of up to R1-trillion. The long-range, cross-sectoral and irreversible aspects of this proposal should have made it a matter for National Development Commission deliberation.

Instead, commissioners have been excluded from this "strategic" decision and a way forward is being charted by an ad hoc committee comprised of vested interests and officials who are already committed.

The National Development Plan contented itself with the modest suggestion that "a thorough investigation" should be conducted into "the implications of nuclear energy, including its costs, financing options, institutional arrangements, safety, environmental costs and benefits, localisation and employment opportunities, and uranium enrichment and fuel fabrication possibilities". There was no mention of nuclear power in the more widely read executive summary of the plan.

The much-celebrated resolution in favour of the plan in Mangaung embraced it only as "a platform for united action by all … to eradicate poverty, create full employment and reduce inequality". If the commission has no role where "strategic" matters, "national interest", or foreign governments are involved, then the ultimate utility of its plan will not be great. It might even end its days as the Reconstruction and Development Programme Mark II.

• Butler teaches politics at Cape Town University.