As others have said, I don't think there's any doubt that as far as geographical spread is concerned, English has to be the most widely spoken language. Even in countries where it is not a native tongue, you regularly see on the TV, cities and towns where road signs, shop signs etc. are in the native tongue and in English too. Again, as others said, International English is the most common language of the Internet as far as the number of countries who use it are concerned.
I acknowledge that as far as population is concerned, English isn't the most spoken language. I personally don't think that is the most important factor though, because if you're the most highly populated country in the world and you're the only country who speaks the language of your country, then it would be wrong to expect all the other nations to learn your language just because of that.
If you want to communicate with the majority of the countries in the world, then English wins hands down. I don't say that out of pride, because I'm English, but because it's common sense and blatantly obvious as the best way to communicate.
If we are moving to a single global language, then English is the most obvious choice AT THIS MOMENT IN TIME.
Regardless of what has happened in the past, concerning the spread of English and to a certain degree, the British Empire, we have to take a reality check and realise that the way things are, are the way things are. Just accept it, without any feelings of animosity towards English or the English speaking people and move on.
As a side note, I very much doubt it's because of any lack of intelligence that the British don't seem to learn as many languages as people from other countries do, but I guess the reason is mostly because the British don't feel they need to learn other languages, when others are learning English anyway. If English is destined to increase with regards to the number of people/nations who speak it, then why bother to learn another language? It would seem illogical to perpetuate the speaking of many languages, when one would suffice. (Admittedly, I say that with tongue in cheek and don't expect others to agree. After all, national pride will always make people prefer to use their native tongue).