Coca~Cola gets its name from the two medicines used in its ingredients:
Coca leaves, from South America, which the drug cocaine is derived from, and Kola nuts. Kola contains caffeine, theobromine, tannins, phenolics, kolatin and kolanin, and is still used in Coca~Cola to this day.

Since started decades after the American Civil War, what was it that made Coca~Cola so popular? There were already plenty of drinks that could have been more popular.
The answer is simple. Coke had a secret formula base made up from processing Coca leaves, the by-product of which is cocaine.
Up to the begining of the 20th century, the Coca~Cola creators did say that their beverage had cocaine.

Coca~Cola did once contain an estimated nine milligrams of cocaine per glass, but in 1903 it was removed.
After 1904, Coca~Cola started using, instead of fresh leaves, "spent leaves"(the left-overs of cocaine) extraction process with cocaine trace levels left-over at a molecular level.
To this day, Coca~Cola uses, as an ingredient, a non-narcotic Coca leaf extract prepared at Stepan Company plant in Maywood, New Jersey, USA.
In the United States, Stepan Company is the only manufacturing plant authorised by the Federal Government to import and process the Coca plant.

For a hundred years now, however, Coca~Cola Company has denied that they ever had cocaine and they deny that it has cocaine now.

Stepan Company is the supplier of cocaine for pharmaceutical trade.
In 1976, (guess who?) George W. Bush, as a Director of CIA, became the Director of Eli Lilly Company which reportedly gets their cocaine from Stepan Company.

Former US President George Bush Senior had been with the CIA since 1959.
He had a company called Zapata Petroleum, later called Zapata Offshore. They had branches around the world.
Among other things, they did offshore drilling for oil, beyond US and other nations' jurisdiction. So dope production centres like Colombia, Bolivia, Peru, Ecuador and others could have helicopters fly to Zepata Offshore drilling platforms.
According to Reuters News some years ago, the helicopters landed there as a transit for dope trafficking.

In 1989, blackmailers, among the top officials of the Food and Drug Administration, began poking around Coca~Cola and asking sticky questions. So Coke lessened the cocaine content in the secret base.
Coca~Cola's US Market share began leveling off.
It had nothing to do with competence or incompetence of their marketing, their advertising personnel or anything of that sort.

On the other hand, elsewhere in the world, sales of Coke outran most every local beverage.
And there were plenty of foreign beverages with traditional flavours. Yet Coke outsold them.
Why? Simple.
For foreign consumption Coke had cocaine secret base.

So those drinking Coke outside America, subconsciously got addicted to Coca~Cola. It made them feel better, some thought it even made certain pains go away.

CONCLUSION
Though Coca~Cola lessened the cocaine content in the secret base for the United States, there is no proof that it did the same for other countries outside the United States of America.