During the Vietnam War - or the American War, as it's sometimes known in Vietnam - Pho Binh was a popular place to grab a hot bowl of traditional pho bo, or beef pho.

The restaurant was just a few hundred feet down the road from the U.S. Military Police headquarters in what was then Saigon, and U.S. soldiers were known to sometimes eat there.

What those soldiers didn't know was that one of the servers ladling out their beef noodle soup was Ngo Toai, a leader of the Vietnamese resistance.

Toai had established the floor above the restaurant as a secret meeting place for the city's Viet Cong.

The Tet Offensive, one of the largest and most important military campaigns of the war, was actually, in part, planned there in 1968 - all while U.S. soldiers were downstairs slurping their noodles, none the wiser.

Hi, I'm Justin Dodd, Welcome to Food History.

Pho is a delicious dish, but it also tells us a lot about the history of Vietnam, and about how cultures collide.

Case in point: The name pho might have French origins.

Feu, spelled F-E-U, is the French word for fire, and pot-au-feu is the name of a rustic beef stew in French cuisine.

Some people argue that the similarity of pho and feu shows that the Vietnamese soup was directly inspired by the French.

It's easy to see why they'd draw that conclusion.

France colonized Vietnam from the late 19th century through the first half of the 20th century, and it had a big impact on Vietnamese cuisine, from the baguettes used for banh mi to the Vietnamese names for ingredients the French introduced to the country.

Potatoes, for example, are known as khoai tay (kwai tae) in Vietnam, which can be translated as "Western yam."

By the way, you can learn way more about potatoes in the first episode of Food History.

Or "pho" could come from Cantonese.

It's kind of complicated.

Not everyone is convinced that pho comes from the French, though.

Before pho, a noodle soup known as xao trau, made with slices of water buffalo meat, was already popular in Vietnam, according to an essay by Dung Quang Trinh.

Because so many of the street vendors selling the soup were Chinese, a Vietnamese-Cantonese name for the dish, nguu nhuc phan, or “beef with rice noodles,” was often used.

Trinh suggests that, over time, that name may have been shortened to phan a or phon o, and finally settled into one word, pho.

One reason why it wouldn't go by phan?

It might sound a little too much like phan, which means poop.

Not a very appealing thing to be yelling out to attract customers.

So while Chinese and French culture might have both helped influence pho, it's difficult to pinpoint exactly where the word came from.

Pho is a melting pot, in more ways than one.

Before French colonization, beef was not very common in Vietnamese food.

It was more common to have cattle work the fields than to slaughter them for dinner.

When the French arrived, they brought with them their love of beef, and it became a lot more widely available.

Using the bones that were left over from beef production was a simple and economical way to infuse flavor into a dish.

The addition of rice noodles and aromatics like onion, ginger, star anise, and cardamom helps transform the simple beef broth into a complex and comforting meal.

It's a Northern/Southern thing.

The early pho that originated in Northern Vietnam is called pho bac, and for some pho purists it's still the gold standard.

It consists of rice noodles, a clear broth made from beef and spices, and some thinly sliced beef on top.

Pho nam, or southern-style pho, didn't appear until South Vietnam was split from North Vietnam in 1954.

Southern Vietnamese cooks are generally a lot more liberal with their garnishes and condiments, which can include Thai basil, cilantro, lime, bean sprouts, chili peppers, fish sauce, and hoisin.