Earlier this month, a pronouncement by China fueled rallies in a number of car companies, both Chinese and non-Chinese. But as is usually true when it comes to China, there are layers of meaning to peel away to get at the more significant story.

The announcement was that China planned to ban the sale of cars with internal combustion engines, as a few other countries, including Britain and France, had previously said they planned to do. The market took the words to heart as signaling a big boon to makers of electric vehicles, with China’s BYD Company (OTCMKTS: BYDDF) – a denizen of our Real World Investing portfolio (and a company 25 percent-owned by Warren Buffett) – leading the way with a 50 percent gain. Other Chinese automakers including Geely (OTCMKTS: GELYF) also were up sharply, while General Motors (NYSE: GM) and Tesla (Nasdaq: TSLA) staged rallies as well, though a bit less vigorous than for their Chinese competitors.

The rallies in the non-Chinese automakers likely reflected reports that China might loosen its requirements on ownership of foreign ventures. Currently foreign companies that want to operate in China must do so as a joint venture with a Chinese company that is granted a majority share. It has been widely bruited that future foreign auto projects domiciled in China might be allowed to function with majority foreign ownership. Some stories even suggested that foreigners – subject to certain provisos, such as a severe limit on exports – might be permitted to keep 100 percent ownership.

Returning to China’s plans to ban gasoline-powered car sales, as I suggested above it rarely pays to take what China says at simple face value. It’s not that I think the government is outright dissembling. Rather, I suspect that China has additional agendas beyond the surface goal of slashing pollution.

One clue came just one day after the announcement was made, when the Chinese government announced it was pushing off the launch date for its plans by a year, to 2019 instead of 2018. Those plans called for carmakers to institute a type of cap and trade system in which they are assigned quotas for electric cars. Companies that fall short will have to buy points from companies that exceed their quotas. Carmakers had balked at having to implement the requirements so quickly. The fact that the government so quickly changed the starting date bespeaks the ad hoc nature of these noble plans.

And it raised in my mind the question of why the government had bothered to announce the goal without ever offering a year by which it expected to achieve it. That, in turn, brings up yet another issue. China has said that it wants to sell 7 million electric vehicles a year by some time in the 2020s, a figure that would represent approximately 20 percent of the country’s total car sales by then. Getting to 100 percent from 20 percent is clearly going to be a long haul. Estimates by Bloomberg, which is among one of the most optimistic analysts when it comes to the future of EV’s, suggest it won’t be until 2038 that worldwide EV sales surpass sales of conventional cars. And how long after that will it be before only EVs are being sold? Remember, what counts when it comes to pollution from vehicles isn’t single-year sales of EVs but rather the percentage EVs represent of the entire universe of cars on the road. The above brief analysis suggests that EVs won’t be making a major dent in that universe until 2050 or later.

Here’s the point: the Chinese do, indeed, want to ramp up EV production as fast as possible. But common sense suggests that the announcement about replacing conventional sales with EV sales not only was premature in that China hadn’t worked out the details, but also wasn’t particularly meaningful.

So why the hurry in making the announcement? As I detail here, the Chinese have secured for themselves supplies of virtually every critical component needed to make both the engines and the batteries of EVs. By proclaiming its commitment to EVs as a pollution-fighting government priority, China has created a perfect cover for keeping these materials for itself.

Moreover, China’s plans to export EVs suggest designs on the car market far from the borders of the Middle Kingdom – and lead to a second example of China presenting a policy that seems to mean one thing but that contains concealed layers of meaning. If at some point China does allow some foreign car companies to keep 100 percent ownership of their Chinese operations, what would it really signify? After all, with the system of points and quotas, China will be maintaining a lot of control over its domestic car markets. Sure, foreign car companies, Tesla for instance, might be allowed full ownership of what they make, but what they make, and where they can sell (probably only to China citizens) will likely be controlled by Beijing, which will make sure that its companies are the ones benefiting from exports.

Tesla’s Elon Musk is brilliant and charismatic, but those characteristics won’t translate into worldwide EV hegemony if China controls all the materials Tesla’s cars need, which is why for the long run we continue to favor BYD and other Chinese automakers over Tesla. In our hearts we’re rooting for Musk, but at this point the ultra-hyped automaker is more akin to a lottery ticket than a rational investment, and as a rational investor you should insist on better odds.