What’s in a name? In Southeastern Europe, one name change could expand the largest alliance in the world.

Since Macedonia was formed in 1991, Greece has objected to its name because a northern portion of its own country is called Macedonia. And ever since, Greece blocked Macedonia’s request to join NATO.

But now Macedonia has changed its name to “North Macedonia,” and the small tweak was enough for the Greek parliament to become the first country to ratify North Macedonia’s ascension to NATO.

On Thursday, North Macedonia was at the table at the NATO Foreign Ministers’ Summit in Washington, D.C., for the first time as an official invitee. What exactly changed? The foreign ministers of Greece and North Macedonia sat down with the PBS NewsHour for their first ever joint interview.

“What we have tried with our neighbors to do is to diffuse the nationalism, the poison of nationalism, which is something quite different than patriotism [in] the region which was always the powder keg of Europe,” Greek Foreign Minister Georgios Katrougalos said. “We love both of us, our countries, but it is not necessary to hate the country of the other.”

The two countries’ reconciliation “extends the zone of stability in a region that needs more stability,” said North Macedonia Foreign Minister Nikola Dimitrov. “And it makes us an ally that the U.S. and other allies can rely upon.”

Asked whether President Donald Trump’s prior questioning of NATO’s relevance meant the U.S. commitment to NATO was in doubt, Katrougalos delivered veiled criticism.

“We both want to keep this partnership alive and kicking, but in order to do that, there are some things that are necessary to do any kind of relationship: Mutual respect. Not unilateral movements. So we’re going to do our part in Europe,” he added, “and we’re expecting our American friends to do the same.”

North Macedonia still faces many challenges, regional analysts say, including corruption and patronage, media independence, and rights of minority ethnic Albanians. But Dimitrov said the security provided by the country eventually joining NATO had already provided prosperity.

“We are already feeling that predictability essentially triggers” economic growth, he said.

U.S. officials say solving what used to be referred to as an “intractable conflict” between the two countries would help combat Russian influence in a critical region. But both foreign ministers held out hope of working with Russia, not against it.

NATO will, at some point, “need to have a dialogue, to de-escalate the renewed tensions that started with Georgia and then Ukraine. But this bridge will have to be built on some important pillars, where international law is very important,” Dimitrov said. “And I think we will help in our own way as the 30th member state.”