French leader and his American counterpart mark Bastille Day in Paris

France’s Bastille Day parade on Friday coupled traditional displays of military might with a look at wars past and present and a nod to the U.S. role in both.

French President Emmanuel Macron invited Donald Trump as the guest of honor for the celebration to commemorate the 100th anniversary of the U.S. entry into World War I. The two men sat side by side with their wives, speaking animatedly as American and French warplanes roared above the Champs—Elysees.

Two hours before the parade Friday, the famed Champs—Elysees avenue was emptied as was the Place de la Concorde with its golden—tipped obelisk. The wide boulevard has been targeted repeatedly by Islamic extremists, most recently last month when a man crashed his car into a convoy of gendarmes.

Five of the 145 U.S. troops marching in Friday’s parade wore period World War I uniforms; Trump saluted the detachment as it passed.

Also in the parade were French soldiers taking part in the mission against the Islamic State group. France and the United States are among a coalition of nations fighting the extremist organization.

Trump was expected to return to the U.S. after the parade and Macron heads to the southern city of Nice, where last year an extremist plowed a truck into the holiday crowd, killing dozens. IS claimed responsibility for that attack and others in France, including one just last month on the Champs—Elysees that left only the attacker dead.