What is preventing UN from playing a more assertive role atleast in Global Pandamic situation?

Question

During the COVID-19 pandemic, the UN member nation's response was more or less defined by the country leaders' personality. WHO guidelines were generally followed and acted upon. However, few dangerous exceptions were also witnessed. COVID -19 has brought out a large number of inadequacies in handling global pandemic. A few of them are:-

1. Under-reporting of cases.
2. Outright denial of cases.
3. Inadequate adoption of guidelines.

The International Health Regulations (2005) is a "legally-binding set of regulations" IHR. However, in the FAQ, it has the following clarification:-

7. How will compliance with the IHR (2005) be achieved? WHO IHR

Although the IHR (2005) do not include an enforcement mechanism per se for States which fail to comply with its provisions, the potential consequences of non-compliance are themselves a powerful compliance tool.

The cause of concern for this type of regulation is "potential consequences of non-compliance" are not affecting leaders of few countries. Their action can have grave implications if future pandemics are more fatal than COVID-19.

What is preventing the UN from playing a more assertive role, at least in Global Pandemic situations?

Answer 1

A greater role for the UN would set a precedent that could be applied on others disasters, like the ongoing climate change or refugee movements.

• There is the principle of national sovereignty. Powerful members, including veto powers on the UNSC, are not willing to grant the UN greater responsibility.
• Limited funding, and an unwillingness to provide funds for international cooperation without strict controls how it would be used.
• Unwillingness to share specialized resources until the own population is cared for.

Answer 2

I'm not even sure a centralized decision-making organ would be such an improvement, although coordination and assistance, via the WHO, is essential.

Consider that actions have varied widely and patterns of what works/doesn't weren't clear at first:

• Sweden's herd immunity was a fail
• Experts first criticized China's Wuhan quarantine, and also masks. And travel bans.
• Singapore was praised, until it wasn't

...and so on.

With new situations, experimentation is key: enforcing only one approach could turn out to be a very bad idea.

Not to say there is no place for more UN, not at all, only that it's tricky to get right.

Otherwise, I agree with o.m. answers that countries see it as infringing their sovereignty and possibly tying them with future obligations. As ever, UN guidance remains largely advice, rather than binding.