Why we cannot take our national debt and its percentage of GDP at face value

According to Pak Sako,

'Former prime minister Mahathir Mohamad claimed last week that Malaysia's current debt level is “healthy” compared with Greece's.

But the debt-to-GDP percentage Mahathir relied on tells next to nothing about the full extent of Malaysia's debts; the nature of these debts; or what can happen next.

The real devil lies in the details, namely:
(i) the trend in the debt level...
(ii) the causes of debt...
(iii) the types of debt, both known and “hidden”.

How much of the debt is borrowed from the savings of citizens (internal debt)? How much is borrowed from foreign lenders (external debt)? How much of these debts is government debt, and how much is private?

A big chunk of Malaysia's debt, RM467.4 billion as of September 2012, is internal debt (Bank Negara Malaysia, Quarterly Bulletin, Third Quarter 2012).

This is the portion of debt that is popularly spoken about — the debt-to-GDP percentage of 53% involves almost entirely this debt.

This is money borrowed domestically from the savings of citizens. It is money belonging to individuals taken from the Employee Provident Fund (EPF), Tabung Haji, pension funds and other social security organisations and institutions (see 'Debt growing but manageable, says MOF', The Malaysian Insider, 28 September 2012)...'

More where that came from:
http://english.cpiasia.net/index.php?option=com_content&view=article&id=2483:investigate-malaysias-debts-now&catid=219:contributors&Itemid=189

Link