President Donald Trump's clash with scores of professional football players who knelt during “The Star-Spangled Banner” last weekend has set off a heated debate over proper etiquette during the national anthem. But the U.S. is far from alone.
Throughout the world, flags, anthems and other national symbols can often divide as much as they unify, especially in countries with large religious or ethnic divisions.
Here is a look at some of the controversies:
Israel's Arab minority has long felt disconnected from the national symbols of the Jewish state.
Israel's national anthem “The Tikva,” or “the hope,” expresses the yearning of Jews to return to their ancient homeland. The Star of David is emblazoned on the flag and the national emblem is a menorah, a candelabra used in the biblical Temple in Jerusalem.
Arabs make up about 20 percent of Israel's citizens. But they often face discrimination, and many feel alienated or identify with their Palestinian brethren.
Some Arab players on Israel's national soccer team have expressed discomfort when the anthem is played before matches. An Arab lawmaker, Hanin Zoabi, boycotted the national anthem when she was sworn into Israel's parliament.
Arabs are not the only minority in Israel to reject its national symbols. Some ultra-Orthodox Jewish sects are anti-Zionist, and members refuse to join the army or participate in national moments of silence on two separate days of remembrance - for fallen soldiers and Holocaust victims.
China's national anthem, “March of the Volunteers,” has occasionally been a political flashpoint in the semiautonomous region of Hong Kong.
Soccer fans in Hong Kong, where tension is rising over mainland China's growing influence, have been known to boo the anthem when it's played at games between the home team and teams from China or other countries. FIFA, the sport's governing body, has responded by fining the local soccer association.
The Beijing government passed a new law this month that makes improper use of the anthem punishable by up to 15 days in prison. Pro-democracy activists and lawmakers fear it could be used to undermine freedom of speech in Hong Kong.
It's unclear how the law will be implemented in Hong Kong, which has a separate legal system from the mainland.
One of Vladimir Putin's most resounding steps in his first year as president in 2000 was to re-introduce the Soviet anthem to replace “The Patriotic Song” by the 19th century composer Mikhail Glinka, which was Russia's anthem between 1991 and 2000.
Putin floated the idea in the fall 2000 after some Russian athletes publicly complained that the Patriotic Song has no lyrics and they could not sing along as athletes in other countries do. Soviet poet Sergei Mikhalkov, who authored the original lyrics for the Soviet anthem, was commissioned to write the new ones.
Liberal politicians and media criticized the return of the Soviet anthem as an ominous harbinger of a rollback on reforms and freedoms brought about after the fall of the Soviet Union.
Japan's anthem “Kimigayo,” or “your reign,” was taken from an ancient poem and widely known as a song dedicated to the emperor.
The song has long been controversial and is still politically sensitive because it was once used to glorify the emperor and to drum up support for Japan's wartime militarism, prompting some pacifist teachers and students to refuse to stand up and sing at graduation ceremonies or other commemorative events.
“Kimigayo” was officially stipulated as the national anthem in 1999 following years of pressure by Japan's conservative ruling party, and singing it has been mostly enforced at most public schools, in part due to fear of punishment for failing to do so.
Singing “Kimigayo” and hoisting the national flag is often considered a rightwing statement, though it is less so now, while ultra-rightists typically use the Rising Sun flag in their social media cover photos.
Germany bans any display of the Nazi red, black and white flag with the swastika, as well as any other symbols from the period.
Violating the ban can lead to charges of incitement. It also bans the use of any Nazi anthems and even things like the stiff-armed so-called “Hitler salute.”
That led to difficulties for several tourists this summer - one American and two Chinese - who were investigated by police after giving the salute in public.
India has long been touchy about perceived slights to its national symbols.
Though Indian law doesn't require people to stand when the country's national anthem is played, a Supreme Court ruling last year demanded it from all citizens. The court also ruled that movie theaters must resume a tradition of playing the anthem before any film, and said all those present “must stand up in respect.”
Citizens caught burning or otherwise desecrating India's tri-color flag can also be punished by up to three years in prison. But nothing irks the country's leadership more than maps that question the country's borders.
The issue has most often flared over the borders drawn around the disputed Himalayan region of Kashmir, which Pakistan also claims, as well as the northeastern state of Arunachal Pradesh, contested by China.
India routinely criticizes its neighbors as well as companies like Google or Twitter when they publish maps ascribing Indian-controlled territories to either Pakistan or China. Last year, lawmakers drafted legislation threatening up to $15 million and seven years in prison for drawing and publishing an incorrect map.
President Abdel-Fattah el-Sissi, a former general, has emphasized patriotism as a cornerstone of his political discourse since taking office in 2014. His public displays of patriotism, like ending speeches with “long live Egypt!” three times, has fueled nationalism, even jingoism, in media loyal to him.
For the first time in living memory, on the first day of classes in state universities this month, students saluted the red, black and white flag as they chanted the national anthem.
The new practice, which is not obligatory, was celebrated by the pro-government media as a welcome demonstration of patriotism, but also provided rich material for satire on social media.
In 1995 at the European basketball championship in Athens, there was controversy during the medal ceremony right before the winning Yugoslav team, made up mostly of Serbs, were about to receive their gold medals.
The third-placed Croatian team, in an unprecedented move, stepped down from the medal podium and walked off the court minutes before the old Yugoslav anthem was to be played. The two former Yugoslav republics were at war in the 1990s. Even today, when they meet in sports events, the anthems are loudly booed by the fans.
Malaysia apologized to its much bigger neighbor Indonesia last month for an “unintentional” mistake in printing the Indonesian flag upside down in a souvenir guidebook for the 11-nation Southeast Asian Games it was hosting.
The error made the red-and-white Indonesian flag resemble Poland's and caused anger in Indonesia, where “shameonyoumalaysia” became the most popular hashtag on Twitter.
Indonesia's President Joko Widodo demanded an apology but also cautioned against exaggerating the incident.
France hasn't seen take-a-knee protests, but there has been a long-running debate over whether French soccer players should sing the national anthem at international matches. Many French players don't, but it's generally out of indifference instead of political protest. The issue resurfaces at the World Cup and other soccer tournaments, often raised by the far right.
France has seen taunts from fans during the national anthem at soccer matches in the past, notably from Corsican separatists and French fans of North African descent. As interior minister in 2003, Nicolas Sarkozy backed a law that made it a misdemeanor to insult the national flag and anthem.
More broadly, French national symbols were long associated with the nationalist far-right, and it was seen as OK in many quarters to snub them. Attitudes have shifted as France has faced terrorist attacks in recent years, and it's becoming more and more common to see people of varying political views flying a French flag and singing the anthem.