A century separates America's entry into World War I and 2017, but some of the same issues roiling society then are manifest today. Be it debates over the country's place in the world, its military mission and preparedness, European alliances, the U.S.-Mexico relationship, civil and women's rights, the balance between civil liberties and national security, terrorism and other schisms, America is a nation still riven with divisions.

"It's almost unbelievable how contemporary and relevant what was going on between 1914-1918 is to today," said Mark Samels, executive producer of "The Great War," a riveting three-part "American Experience" documentary that will run April 10-12 on PBS.

"The first world war took place at a time when America was changing rapidly and Americans were changing rapidly," Samels said. "You had this cataclysmic world event that occurs and it forces Americans to ask themselves, 'Who are we? Who are we as individuals and who are we as a country?' And I think that we're in a moment that's similar to that again."

November's election revealed that Americans are still split on our role in the world, and, as is the case now, in 1917 the perception of that role shaped opinions on military readiness.

In fact, "preparedness" became a rallying cry and code word as the conflict convulsed Europe.

"If you were for preparedness, that meant you were a militarist," said Brian Horrigan, exhibit developer for the Minnesota History Center's "WW1 America" exhibit that opens April 8.

"Preparedness and peace" were binary narratives at the time, said Horrigan, who added that's also when the modern peace movement began, with most of its key leaders women who were fighting their own battle to get the right to vote.

As for African-Americans — including the throngs streaming north in "the great migration" — many fought abroad while beginning battles for equality at home. Those years were "the seed bed for the civil rights movement," Samels said.

While transformative progress has been achieved on civil and women's rights, equity issues are still prominent in politics and society today.

And just like today, at issue wasn't just America's relationship with Europe, but the neighboring nation of Mexico, as another northerly exodus was taking place as refugees fled their country's revolution. That wave created its own tensions, but suspicions soared after a decoded cable from the German government suggested an alliance that would allow Mexico to reclaim some southwest states should Germany win the war.

Today tensions are rising with Mexico once again, given President Trump's pledge to build a border wall paid for by Mexico.

And America is once again immersed in an immigration debate, just as it was a century ago.

Fear of what were then called "hyphenated Americans" was heightened to a point that it was used as a "cudgel," Horrigan said, adding that some immigrants were considered "subversive and not loyal, with a great emphasis on Americanization and keeping people out."

And 100 years later?

"There is a great emphasis on keeping people out," Horrigan said.

The balance between national security and civil liberties that's subject to so much discussion today took place then, too, but with a much more severe societal and governmental reaction nationally and especially in Minnesota, as described by the Star Tribune's D.J. Tice in his March 12 column.

In New York, a military preparedness parade marched under the banner of "ABSOLUTE AND UNQUALIFIED LOYALTY TO OUR COUNTRY," as evidenced in a photograph in the History Center's excellent exhibit. Other photos testify to the social upheaval, as well as the social force of celebrities selling war bonds, and by extension the war, like an indelible image of Douglas Fairbanks hoisting fellow movie star Charlie Chaplin to a delighted crowd at a massive rally on Wall Street.

Far from the East Coast, the Western Front featured mechanized warfare that accelerated the scale and efficiency of killing, sparking an argument echoed in today's debate over drones and other increasingly lethal technology.

New to the arsenal were chemical weapons, which are still a scourge in Syria and elsewhere today.

And asymmetric tactics like terrorism hit here at home, further fraying a frazzled society.

The "war to end all wars" didn't. But unlike some conflicts, concepts fundamental to our national ethos motivated Americans. "We went to war over an idea: making the world safe for democracy," Samels said. In the process America emerged as a changed nation, and in turn changed the world.

"It was the transformational moment of the 20th century," said Horrigan. "There was the sense that we had done something right, had done something good, had changed the world, had stopped the German military menace. That was something that was widely held and they were proud of it."

That pride was justified. And the epic episode that forever altered America offers lessons for today's turbulence.

"We emerged through it stronger," said Samels. "We didn't emerge completely united, we didn't satisfy all the aspirations of everybody, but we came out a different, stronger nation that would accomplish a great deal in the 20th century. It is a reminder that there is a resiliency and that there is a meaning to being an American, and that meaning is very bound up in ideas and ideals. Reconnecting with that Americanness is a good thing right now."

John Rash is a Star Tribune editorial writer and columnist. The Rash Report can be heard at 8:10 a.m. Fridays on WCCO Radio, 830-AM. On Twitter: @rashreport.