Austria on Tuesday significantly tightened its coronavirus disease (COVID-19) lockdown, closing non-essential shops and most schools and requiring people to stay at home where possible. Across Europe, many countries have been instituting a range of restrictions, including some partial lockdowns as well as a few stricter ones, to try to stem a devastating second wave of the pandemic. COVID-19 cases are increasing around much of the world, and North America and Europe are experiencing the sharpest increases in infection rates. The US never brought rates far below the initial wave, despite some improvement in the summer; nonetheless, it is experiencing a severe spike in cases that is much worse than earlier in the pandemic. Canada successfully brought rates far down in the summer after its first wave in the spring, but now it is suffering through a second wave far worse than the first. Europe also had significant success in combating the virus early in the summer, but its second wave is far exceeding the rates of the first. There were some positive signs in a few European countries last week, with the increase in infection rates slowing — likely indicating some impact from lockdowns and other mitigation measures. Still, the situation throughout Europe is harrowing, with nearly all countries struggling to contain the virus. The second wave of COVID-19 has spread throughout Europe, from the UK to Russia and Sweden to Spain. Even Central Europe, which escaped much of the first wave, is now experiencing very high infection rates. Reactions across Europe have varied. Sweden still leads among those who think the best approach is to suggest, rather than require, some simple precautions while generally keeping everything open. It has had significantly more infections and deaths than its Nordic neighbors but fewer than some other European countries. Multiple countries have imposed a range of restrictions, and several — such as Germany — have put partial lockdowns in place. A smaller number, such as France and Austria, have tightened their earlier partial lockdowns. Officials have warned Europeans that there might be restrictions on travel over next month’s Christmas holiday. It is difficult to pinpoint a single reason for the greater intensity of the second wave of the pandemic in Europe. One factor was the lifting of restrictions over the summer. Similar to Canada, many European countries instituted lockdowns and other measures during the first wave and successfully brought infection rates far down early in the summer. Understandably, many of the stricter measures were lifted. Life returned largely to normal in many places. Unfortunately, it has become clear that a return to normality allows the virus to spread. A related factor is COVID-19 fatigue. Lockdowns are economically and socially damaging; it is not feasible to maintain them indefinitely. Beyond this, many people are tired of other restrictions, choosing not to wear face masks consistently, gathering in larger groups of people, and traveling. When the second wave began in August, many government leaders were reluctant to reimpose restrictions on a weary public and to cause further economic damage. Another major factor that is more specific to Europe was the August travel season. While summer is a time when people from many countries like to travel, European culture particularly highlights August as a time when Europeans go on holiday, and where tourists are often concentrated in specific areas, such as along the Mediterranean Sea. By August, internal European borders were open. While tourist numbers were down from the past, partly thanks to ongoing restrictions against visiting Americans, Europe still had a relatively robust holiday season. It is not a coincidence that infection rates started increasing in August. As vacationers relaxed and socialized — sometimes in large groups without masks — outbreaks began occurring in popular destinations, including ones like Greece that had not previously experienced particularly high infection rates. Travelers then returned the virus to their home countries. In Europe, similar to the US, young adults have played a significant role in driving the second wave. They go on holiday, attend university in some cases, and socialize, and then spread the disease among their families and communities. There are differences between European nations that shape those countries’ experiences. For example, some have been reluctant to promote or require masks, while others have been much more assertive with this key tool. However, even accounting for these differences, the second wave is hitting most of Europe hard. Europe’s experience offers some lessons for the rest of the world. One is that mitigation measures will remain important tools until there is a widely available vaccine or herd immunity. Lockdowns are not sustainable indefinitely, but less restrictive measures can play a key role in helping to prevent surges. Another lesson is to be very careful about large groups of people traveling to a limited number of destinations within a limited period of time; this type of concentrated travel can quickly spread the virus across countries. Finally, no population group — including young or old — exists in isolation; in a society, people of multiple generations, classes and more interact. Their behavior affects each other, especially in a pandemic. Kerry Boyd Anderson is a writer and political risk consultant with more than 16 years of experience as a professional analyst of international security issues and Middle East political and business risk. Her previous positions include deputy director for advisory with Oxford Analytica and managing editor of Arms Control Today. Twitter: @KBAresearch