Over on The Linguist on Language, Steve Kaufman "hazards a prediction" that the current economic crisis might lead to a crisis in confidence in the English-speaking world and that "it may not be such an obvious given that English has to be the international language." Steve also says that it's all in the attitude toward English, that it's a kind of fashion. I disagree with those two statements; it's not about attitude, it's about numbers, and the numbers show English very likely to remain the de facto lingua franca for a very long time to come.
But before I back that up, let me first kick off with where I agree with Steve. I think we will see multilingualism on the rise. Part of it - and I agree with Steve wholeheartedly on this point - is that it's not a big deal to be multilingual, and I think more and more people are coming to that realization. I also think it's quite likely that certain languages might take on a regional nature. While I don't see German supplanting English in Europe, or Russian maintaining its preeminence for much longer in Eastern Europe among the Westward-facing post-Soviet Bloc generations, Chinese is a sure contender to gain some regional clout. The high ratio of Koreans and Japanese in my own and many others' Chinese classes in Beijing is a sure sign of this. And, generally, as the relative size of English-speaking economies decline as countries like China, India, and Brazil continue to grow, multilingualism undoubtedly will get a boost.
That said, I don't think English is going to lose its spot as the world's de facto lingua franca to become just one of several important or regional languages. The numbers that best demonstrate this are how much of world GDP can be allocated to each language. What these numbers suggest is perhaps no major shocker: the continued dominance of the English language, albeit in a gradual decline, and the slow uptick of Chinese, with most other languages' positions not changing very much.
Point by point, here's why I disagree with Steve.
First, the English-speaking world continues to maintain the largest portion of world GDP: around 30%. While this is gradually declining and will continue to do so for a long time to come before leveling off, it's likely to remain in the first position for quite a bit longer, and there's no foreseeable end to it being one of the top languages. Indeed, the only contender with the growth patterns to even possibly supplant English as the language representing the largest portion of the world GDP is Chinese, so at worst English will fall to second place. I believe that economic power correlates directly to the demand to study a language, as can be seen clearly in the widespread interest in English and the growing interest in Chinese.
Second, those statistics don't even consider those who speak English as a second language. Adding those in, it becomes clear why Latin Americans who meet with Arabs who meet with Chinese who meet with Japanese all tend to use English to speak with each other. I worked for a while in the Japanese legislature in the office of a representative with great connections with the Arab world, having attended college in Egypt. At one meeting with some Arab visitors, one Arab guest lamented that it was a shame that they had to conduct meetings in English, and some platitudes were jointly issued about learning each other's languages. While I haven't checked in on this issue lately, I'd be pretty content to wager a substantial amount of money on the fact that those meetings are in fact still going on in English.
Third, there are costs involved in switching from a single standard to multiple standards. If Japan actually sought to carry out the goal of reaching the general level of proficiency in Arab needed to carry out such meetings, countries speaking maybe a dozen other languages would line up for similar treatment. How much money would Japan need to spend to develop such a language proficiency in so many languages? Even if they just added Chinese and Spanish to the mix, you'd still be looking at much greater costs than the current Japanese set-up of a primary focus on English with other languages being more or less extracurricular. While there are certainly very strong arguments to be made that the money in Japan's language-learning efforts could be much better spent, the fact still stands that it will cost more to learn several versus just learning one.
Fourth, there's no obvious contender to take over as the world's lingua franca. Of all the other important languages, China is at about 13% and rising as a portion of world GDP and all the rest are no more than 7% and remaining relatively constant, and I don't think adding in second-language speakers would change those numbers greatly. And could you imagine Guatemalans meeting with Nigerians and conducing the meeting in Chinese? At this point, the idea is still laughable. Even regionally, there are few viable contenders aside from Chinese.
So, without knowing anything further about a student trying to pick their first foreign language to study, I would continue to give the same general advice I've been giving thus far: if your mother tongue isn't English, that should be your first target, as it remains the most economically useful of all languages.
Related: The (roughly) top 20 languages by GDP