"You shall know who the Jordanians are," the armed forces warned in a statement.
Such words could have come straight from the mouth of the King himself -- a former major general in the Jordanian army.
Queen Rania consoled the grieving wife of the pilot who was burned alive in a cage. The Queen, a mother of four, took to the streets of Amman with thousands of Jordanians to honor al-Kasasbeh and condemn his killers.
They chanted: "Long live the King."
Here are five things to know about the royals and the ramifications of Jordan's war on ISIS:
Who is King Abdullah II?
The opening line of the King's official profile
lays out his place in the Hashemite dynasty as the "41st-generation direct descendant of the Prophet Mohammad."
He inherited the Hashemite crown in February 1999
following the death of King Hussein. The dynasty has held power in Jordan since 1921.
Abdullah, 53, was a political unknown who was catapulted into the limelight when his father, before he died, pushed aside the crown prince, Abdullah's uncle Hassan, as heir to the throne.
The son of King Hussein's second wife, the British Princess Mona, Abdullah headed Jordan's special forces, a critical position in a country where the army is one of the throne's important pillars.
Educated in Britain and the United States, Abdullah was seen as a bridge between traditional Arab values and the surging westernization of Jordan's younger generations.
He attended St. Edmund's School in England, and Eaglebrook School, followed by Deerfield Academy, both prep schools in Massachusetts. His command of the English language is greater than his Arabic -- which has raised some eyebrows at home.
His lack of experience when he became King led some to question his ability to hang around long in one of the world's roughest neighborhoods.
His official biography describes Abdullah as a "man of action" even as a young prince. He flew helicopters, planes and parachuted. He has a passion for cars and motorcycles. He is a former Jordan National Rally champion. A Trekkie, Abdullah appeared as an officer in a 1996 episode of "Star Trek: Voyager."
In a country the size of Maine, with staggering unemployment and a widening gap between rich and poor, the new monarch was known to venture out incognito to get a feel for the problems plaguing ordinary Jordanians. He visited hospitals and government offices in disguises, including wigs and a fake beard.
"The greatest fear I have, as time goes on, you can very easily become isolated," he told CNN in 2000.
Who is Queen Rania?
Rania Al-Yassin met Abdullah in 1993. They were engaged and married that year.
Queen Rania has become known for her philanthropic work, pushing for better educational facilities for Jordan's school children and supporting efforts to empower women.
Some see Rania, 44, as a symbol of the contradictions that still blight the region as it tries to come to terms with modernity.
She is the business graduate who left her job at a multinational to marry into a monarchy that has ruled Jordan for decades -- at times an iron rule.
She speaks passionately about freedom of speech and equal rights while Jordan's own human rights record under Abdullah has hardly been exemplary, including harsh laws to clamp down on public dissent and arrests without trial of government critics.
Jordan also has a high number of honor killings -- the practice of women being killed by male family members if they engage in premarital sex.
Rania has spoken out against honor killings, but Jordan's Parliament has opposed legislation that would classify the acts as homicides.
"I personally think that Islam, in and of itself, does not subjugate women and does not hold them back," she told CNN in 2008
. "But certain people choose to interpret Islam in a way that does hold women back. Holy scripture does not hold women back. It's the people that decide to interpret it in such a way for their own, sometimes political, agendas."
Asked if she is criticized for not wearing a traditional veil, Rania said, "Absolutely ... very often. But likewise, there are many women like me who do not wear the veil. So, as long as it's a choice. I have nothing against the veil. And I think that wrongly, many in the West look at the veil as a symbol of oppression."
The daughter of Palestinian parents, she is aware of the social problems that conflict has created in the region. And being a Palestinian has helped in a country where nearly half the population of 7 million is of Palestinian origin.
In her Twitter account
Rania describes herself as "A mum and a wife with a really cool day job."
She has said she sees the Internet as a force for free speech, and that greater communications make it harder for authoritarian regimes to stifle expression.
Still, some Jordanians see her as an outsider. In towns like Mafraq, near the Syrian border and traditionally a bedrock of support for the monarchy, there has been a undercurrent of resentment, especially toward Rania's lavish lifestyle.
"His wife can actually be more of a liability than an asset," Michael Rubin, a former Pentagon official and author of "Dancing with the Devil: The Perils of Engaging Rogue Regimes," said in an email, saying her "profligate spending" causes resentment among ordinary Jordanians "at the best of times."
How will ISIS campaign play in Jordan?
Jordan actually joined the U.S.-led coalition of Arab and Western countries against ISIS in September, launching air strikes on targets in Syria, where the group has set up a so-called caliphate that stretches into parts of Iraq.
"The King's tough stance will play well with many Jordanians, as well as the influential Bararsheh tribe of which he was a member," Rubin said.
But will street protests erupt as the disaffected draw inspiration from the ISIS surge across the borders in Syria and Iraq?
The country is 90% Sunni Muslim, and some Jordanians have questioned their monarch's decision to join the coalition.
"The King's reputation among Islamists is already tenuous, and will only grow more so," Rubin said. "In recent months, pressured by the UAE, upon whose financing Jordan is dependent, he has cracked down on the Jordanian branch of the Muslim Brotherhood."
The Muslim Brotherhood -- which was started in 1928 -- advocates a move away from secularism and a return to the rules of the Quran as a basis for healthy families, communities, and states. The Brotherhood has repeatedly called for political reform in Jordan.
"While many in the West might find it enduring that the King is a Trekkie who once even had a Star Trek 'Voyager' cameo, Islamists consider science fiction forbidden because it presumes to know a future that only God can know," Rubin said.
In 2011, when the Arab Spring was spreading across the region, Abdullah announced sweeping political and economic reforms, including the establishment of a parliamentary majority government -- a key demand of protesters calling for changes to the regime.
Jordan's economy at the time was reeling from the global downturn and rising commodity prices. Youth unemployment was high. There were grumblings over gas prices and pervasive corruption
Three years ago, on the eve of a protests in Amman, Abdullah dissolved the country's parliament and called for early elections in a pre-emptive response to a Arab Spring-inspired movement.
Abdullah and his loyal army kept tight control of the social forces propelling the Arab spring. Promised reforms never materialized.
"As Jordan trumpets its reform initiatives, prosecutors are arresting activists and opposition figures for free speech-related offenses," Sarah Leah Whitson, Human Rights Watch's Middle East and North Africa director, said in a January report.
"Constitutional guarantees amount to no more than ink on paper if the authorities don't get rid of penal code articles that are used to undermine them."
Said Rubin of Jordan's disaffected, "It's doubtful they will look kindly upon his tin ear to their suffering during a time of crisis."
Will Jordan's response play better abroad?
The Hashemite Kingdom has been consistently pro-Western, is one of only two Arab states to have a peace treaty with Israel and is an oasis of stability at the heart of a volatile region. It has quietly allowed the American and British militaries to use its territory and facilities as a staging ground.
The United States has supported the King's road map for reform -- which gradually shifts more power to the elected parliament -- as well as demands for a more inclusive political process. At the same time, the tribes don't want to see the largely urban Muslim Brotherhood -- which derives much of its support from Jordan's Palestinian population -- gain power at their expense.
Jordan is seen as a moderating force in the region. It has been a steadfast ally of the U.S. in the war on terror.
In the years after the 9/11 terror attacks, there have been quiet suspicions that Jordan was hosting secret CIA prisons used for the detention and interrogation of terrorist suspects. While the CIA would never acknowledge such an arrangement existed, the closeness of the relationship between the two countries' intelligence agencies managed largely to exist outside the public view.
Jordan has been leery of publicizing the nature of its intelligence relationship with the U.S. Many Jordanians harbor anti-American sentiment.
"Just as Mikhail Gorbachev is more popular outside Russia than inside his country, the same is often true with Abdullah, who gets more respect abroad," Rubin said.
Will the warrior king participate in airstrikes?
A photo of King Abdullah II in a pilot's uniform and black gloves was posted Tuesday on the Facebook page of The Royal Hashemite Court
, leading some people to speculate that he would personally participate in the ISIS airstrikes.
The caption: "His Majesty King Abdullah II, The Supreme Commander of Jordanian Armed Forces, cuts short his visit to the United States of America after the martyrdom of Muath Al Kasasbeh."