It certainly won't be before time. The Japanese giant, so powerful and confident in its domestic market, has always looked weedy and ill-at-ease when venturing beyond it. Small wonder that less than 10 per cent of its revenue is generated outside Japan.
There are sound reasons for this. Despite the fact that it ranks as the industry's fifth-largest holding company, it remains isolated by language - few of its top directors speak English - and by a very different culture.
If it's been a long and tough haul for Publicis to become the first major marcoms group from outside the US or the UK to transform itself into a credible world player, imagine how much more difficult it will be for one from Japan.
Unlike its multinational clients, Dentsu has never managed to export its brand around the world. Instead, it has relied on some questionable acquisitions and alliances in which its overcautiousness made it play too passive a role.
Now, Dentsu seems to be overcoming its reticence. Most commentators would argue that it has had little choice given the faltering state of Japan's long booming economy and the threat of being left behind by a marketing industry transformed by technology and globalisation.
What's more, 2012 will be a defining year in the evolution of Dentsu when it will have the option of withdrawing its 15 per cent stake in Publicis and going its independent way.
It's an intriguing prospect given that, even now, Dentsu is a mind-boggling organisation. Its 47-storey Tokyo headquarters houses 6,000 staff, one for each of its clients. It controls more than 30 per cent of its domestic market by revenue and between 40 and 50 per cent of commercial airtime on Japanese TV. It has billings of more than $17 billion.
The consolidation of the global communications industry has long threatened to create a club that's much too cosy. Maybe the time is right for Dentsu to gatecrash it and begin rattling some cages.