(CNN) All across France, blue-white-red national flags flew from buildings on Friday. President Francois Hollande had asked people to hoist the tricolor in patriotic solidarity with the 130 people massacred two weeks ago in Paris.

And in the grand square of the Hotel National des Invalides, Hollande called guests together to mourn the victims in a national ceremony.

Attack survivors appeared alongside grieving families and diplomats representing the countries of foreign victims.

"They were France. They were shot dead because they were freedom," Hollande said of the victims. In the name of the nation, he extended "our compassion, our affection toward the families, the nearest and dearest ... parents who no longer see their children. The children who will grow up without their parents."

Military surroundings

Though the President's words were tender and poetic, the spot chosen for the ceremony was laden with ominous symbolism.

His call to hoist a flag -- and seize it as a symbol of national solidarity and pride -- carries more undertones in France than it does in other countries.

The French flag symbolizes a more right-wing, militaristic nationalism to many in the country. It was embraced by the Nazi-aligned Vichy regime during World War II and during the country's colonial era. (However, the flag is often prominently displayed during sporting events, like the 1998 World Cup, which the country won.)

Paris has many expansive public gathering places, but Les Invalides is a collection of museums and monuments to centuries of French military might. The remains of Napoleon Bonaparte are interred there.

Dignitaries and mourners were flanked by rows of stern-faced troops in ceremonial dress, holding weapons at attention.

And Hollande directed a threat at ISIS on behalf of the people gathered before him.

"I promise you solemnly that France will do everything to destroy the army of the fanatics who carried out these crimes," he said.

Les Invalides was a fitting place for Hollande to stand at the end of a week filled with beating war drums against ISIS.

France at war

Since the November 13 attacks, France has been at war with the militant group, Hollande has maintained, and he has vowed to destroy it. On Monday, French warplanes flew struck at ISIS from the aircraft carrier Charles de Gaulle.

And Hollande's appointment calendar filled with meetings with world leaders, starting with British Prime Minister David Cameron on Monday and ending with a visit to Moscow to speak with Russian President Vladimir Putin on Thursday.

A French fighter jet takes off from the carrier Charles de Gaulle on Monday.

His rallying cry has drawn encouraging, if small, echoes.

Cameron called for Britain "to take action now, to help protect us against the terrorism seen on the streets of Paris and elsewhere." But his Labour Party opposition has said it would oppose the Prime Minister's proposal to expand UK airstrikes on ISIS positions in Iraq to include Syria, citing a lack of coherent strategy.

A conflict of interests

Pulling Russia into the mix has proved testy.

Russia is not a member of the U.S.-led global coalition against ISIS, although on Thursday, Putin said that his country is ready to cooperate with the coalition.

But there is a conflict of interests between Russia's approach to Syria and that of the Western allies. The White House has said autocratic Syrian President Bashar al-Assad must go if there's going to be a peace in the nation torn by war since 2011 -- a belief France shares.

But Russia is an ally of Assad's.

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France and Britain are already part of a U.S.-led coalition that has been bombing ISIS targets, while Russia is conducting separate airstrikes against ISIS but also against more moderate groups that oppose Assad. And Russia has coordinated with the forces of Syria's President.

However, French Foreign Minister Laurent Fabius said Friday that working with Syrian forces could be productive in the fight against ISIS.

"Forces on the ground have to be from the Free Syrian Army, Sunni Arab forces, and why not also from (Syrian) regime forces?" Fabius said in an interview with RTL radio in Paris. He added that Kurdish forces need to be involved.

Fabius later clarified those comments, saying that cooperation with Syria was "desirable" but possible only after a "credible poiltical transition."

Syrian Foreign Minister Walid Moallem said in Moscow that if Fabius was serious about working with the Syrian Army, the Assad regime would welcome it.

Adding to tensions, Turkey, a NATO member and a staunch Assad opponent, shot down a Russian military jet this week, saying the plane had crossed into its airspace and ignored multiple warnings. Russia says the plane had been in Syrian airspace.

Hollande also spoke with President Barack Obama, but the United States has shown no clear sign of budging from its vow against a U.S. ground incursion against ISIS.

Germany reverses stance

Germany is constitutionally hampered in participating in attacks outside its borders, but when Chancellor Angela Merkel visited Paris this week, Hollande reportedly called out his close ally.

In a reversal of its previous stance, Germany committed four high-tech reconnaissance fighter planes and logistical help to the fight against ISIS, Spiegel Online reported.

"When the French President asks me to think hard about what more we can do, then it is a responsibility for us to think hard about it," Merkel said Wednesday.

Photos: The search for Paris terror suspects Photos: The search for Paris terror suspects A Belgian soldier stands guard around a security perimeter as a reported police intervention takes place around the Grand Place central square in Brussels on Sunday, November 22. Multiple raids took place throughout Brussels, according to the Belgium Federal prosecutor, and 16 people were arrested. Salah Abdeslam, a suspect in Paris terror attacks, was not among them. Hide Caption 1 of 16 Photos: The search for Paris terror suspects Belgian police officers and soldiers secure an area as a reported police intervention takes place around the Grand Place central square in Brussels on November 22. Hide Caption 2 of 16 Photos: The search for Paris terror suspects Belgian national Ahmad Dahmani, center, suspected to be involved in the November 13 Paris attacks, was arrested late Friday, November 20, in southern Antalya province, Turkey. Dahmani had been tracked by a police anti-terror unit after he arrived at the Antalya International Airport -- on a flight from Paris -- the day after the massacre. Hide Caption 3 of 16 Photos: The search for Paris terror suspects Two Syrian nationals, Ahmet Tahir, left, and Muhammed Verd, were arrested by Turkish security forces in southern Antalya province, Turkey, on November 20. They were captured, allegedly with a fake Syrian passport for Belgian national Ahmad Dahmani, suspected of location scouting for the Paris attackers. Hide Caption 4 of 16 Photos: The search for Paris terror suspects Police searched the home of Hasna Ait Boulahcen's mother in Aulnay-sous-Bois, France, on Thursday, November 19. Ait Boulahcen, 26, was killed during Wednesday's raid on an apartment in the Paris suburb of Saint-Denis, official sources in France told CNN. She did not blow herself up as was previously thought. Hide Caption 5 of 16 Photos: The search for Paris terror suspects A body is removed from an apartment that was raided by police in the Paris suburb of Saint-Denis, France, on Wednesday, November 18. French special forces were looking for those behind the November 13 terrorist attacks in Paris. The hourslong ordeal ended with at least two suspects dead and eight detained. Hide Caption 6 of 16 Photos: The search for Paris terror suspects Authorities zeroed in on the Saint-Denis building after picking up phone conversations that a relative of Abdelhamid Abaaoud, the attacks' purported ringleader, might be there. The Paris prosecutor's office later announced that Abaaoud's bullet-riddled body was found after the raid. Hide Caption 7 of 16 Photos: The search for Paris terror suspects French Interior Minister Bernard Cazeneuve visits Saint-Denis during the raid on November 18. Hide Caption 8 of 16 Photos: The search for Paris terror suspects A Renault Clio with Belgian license plates is towed by the police in Paris on Tuesday, November 17. The car is believed to have been rented by Salah Abdeslam. Authorities are looking for Abdeslam, a Belgium-born French national who is one of three brothers suspected in the terror attacks. Hide Caption 9 of 16 Photos: The search for Paris terror suspects Special forces stand guard on a roof in Molenbeek, a suburb of Brussels, Belgium, on Monday, November 16. Hide Caption 10 of 16 Photos: The search for Paris terror suspects Armed police guard a street in Brussels on November 16. Hide Caption 11 of 16 Photos: The search for Paris terror suspects Salah Abdeslam's brother Mohammed speaks to the media at his house in Molenbeek on November 16. Mohamed Abdeslam was released by police after being detained over the weekend. Hide Caption 12 of 16 Photos: The search for Paris terror suspects Special forces sit on a roof in Molenbeek as they prepare to enter a house on November 16. Hide Caption 13 of 16 Photos: The search for Paris terror suspects Armed police guard a street in Molenbeek on November 16. Hide Caption 14 of 16 Photos: The search for Paris terror suspects A man is detained by a police officer after a raid in the Mirail district of Toulouse, France, on November 16. French Prime Minister Manuel Valls said there were 150 police raids overnight in the country. Hide Caption 15 of 16 Photos: The search for Paris terror suspects Police officers overlook Paris as they patrol in front of the Sacre Coeur Basilica on November 16. Hide Caption 16 of 16

As France mourns its dead, a key suspect in the attacks is still at large. It has been more than a week since an international arrest warrant was issued for Salah Abdeslam.

Investigators haven't detailed what they believe his role was in the coordinated series of attacks, but police say Abdeslam may have dropped suicide bombers off at the Stade de France and then made his way to another Paris neighborhood. His fingerprints were found in a car connected with the attacks.