And of course a parallel French-language force could be created with la Francophonie
Would you also include Francophile states?
One of the immediate problems is how you would define an "English Speaking Country"?
The language of the largest majority in India, Pakistan, Kenya, Sudan, Tanzania, Phillipines and Nigeria is English.
You would have to put more inclusive parameteres on it, ie. democratically elected, etc...
For a start you may get Austrailia, New Zealand, South Africa, United Kingdom, Ireland and Canada
According to Pattanayak, an Indian linguist, only about 4% of Indians are truly functional in English. They of course are the ones we see all the time. So that puts all the other countries in your list into question. Even Canada is only about 85% English-speaking, and that's self-assessed, so we could probably knock another 10% off of it to bring it down to 75%.
So if we're looking at 'predominantly' English-speaking countries, we'd be looking at Canada, the US, the UK, Ireland, New Zealand, Australia, South Africa and a few others. From my understanding, maybe the Phillipines and Jamaica could be included in the list.
Granted this would not make for the most efficient of alliances, with these countries being so thinly spread out, but that does not make it pointlsee none-the-less. Canada, the US, the UK, and Ireland could prove to be effective staging grounds to secure the North Atlantic Ocean. No, I'm not talking about securing it for ourselves of course, no imperialist venture or anything like that; but just to secure them from any possible rogue force.
New Zealand, Australia, and South Africa could protec the waters in the southern area, and with the US and Canada provide some protection across the Pacific Ocean.
A parallel French-speaking force, in alliance with the English-speaking one but obviously separate administratively for obvious logistical reasons (just as the current Canadian forces are administratively somewhat separate for the same reasons), could also help secure the North Atlantic between Canada, France, and Belgium, while French Guiana and a few other states could help secure the South Atlantic. Of course these forces would not be allied only with one another, but could form alliances with other forces too. The main objective of this would be to have nations sharing a common force to save money in administrative costs. Integration between nations woudl also help make this force more efficient too.