By Carol Ryan

It is a pity for Diageo that America's exceptional drinking habits can't be exported. Returning to growth in other parts of the world will be a fraught process.

The London-based maker of Johnnie Walker scotch and Guinness stout said Tuesday that sales in North America fell just 1% over the six months through June compared with the same period of 2019. Far tougher conditions everywhere else dragged group sales down 23% overall. Management sounded cautious about how quickly demand will recover -- one reason the company's shares fell 6% in early European trading.

North America, which accounts for 39% of Diageo's revenue, has been one of the most resilient liquor markets in the world since the Covid-19 pandemic began. Americans like to drink at home anyway: Even in normal times, only a fifth of all the liquor consumed in the U.S. happens in bars or restaurants, brokerage Bernstein estimates. And the bulk of sales lost in these venues during lockdowns shifted to supermarkets. Consumers spent 38% more on spirits to drink in their homes in the 17 weeks to mid-July than a year ago, according to Nielsen.

Other important markets are structured differently, so will take longer to return to health. Diageo's sales in Europe and Turkey -- the company's second-most important region by revenue -- fell almost one-third in the six months through June. Europe's alcohol market is split fifty-fifty between what is consumed inside and outside the home. So long as consumers are wary of crowded spaces, bars and restaurants will be ordering less beer and liquor from Diageo. The company has already taken back half a million kegs of unsold Guinness from pubs, mainly in Europe and Africa.

The company took a GBP1.3 billion ($1.7 billion) write-down on the value of its businesses in India, Nigeria and Ethiopia. Around 60% of Diageo's sales in Africa are beer, which is mainly sold in bars. Last week, the world's biggest brewer AB InBev also booked a big impairment charge against its African beer business.

Diageo's Asia division may bounce back first. India is an important market for scotch, and consumers there are big home drinkers, like in the U.S. A six-week ban on alcohol sales imposed by the Indian government, which ended in May, should only be a temporary shock to demand.

Diageo's share price is 17% off its January high, but that seems a sensible discount for today's uncertainties. A multiple of 23 times projected earnings is still well above its 10-year average of 19 times. Making a big chunk of sales in the U.S. is a bonus, but viewed from other corners of the world, the business looks much less defensive.

Write to Carol Ryan at carol.ryan@wsj.com