When protecting a high value target, a single point of failure could be a catalyst for a catastrophic breach.
When securing multinationals, consideration must be made for the smaller subsidiaries. They are connected to the corporate network and as any good pentester can tell you, pivoting is a powerful concept.
Smaller subsidiaries may not have the same level of physical, network, endpoint security. Some subsidiaries may face different level of threats: political, socio-economic, domestic instability.
A quick example is an UK multinational operating in Argentina, or Taiwanese company operating in China, could there be repercussions?
On the other end of the spectrum, subsidiaries may not have faced the same level/intensity of threats as their parent company. Psychologically, citizens maintain the perception that being in a safe backwater nation, the developed world threats are not of major concern.
It is important to note that security is a global effort, consider the threat level and adjust to it.