ROME— At a time when North Korea and the United States continue to flex their nuclear muscles, Pope Francis said Friday that a certain pessimism, resulting from the “complex political challenges of the current international scene,” makes the prospect of a world free of nuclear weapons remote.

Nuclear weapons reflect a “mentality of fear,” he said, while insisting that an effective and inclusive effort nevertheless can lead to the dismantling of arsenals.

“The escalation of the arms race continues unabated, and the price of modernizing and developing weaponry, not only nuclear weapons, represents a considerable expense for nations,” Francis said.

As a result, he said, “real priorities” facing humanity, such as the fight against hunger, educational development, protection of the environment and the promotion of human rights, have been relegated to second place.

“International relations cannot be held captive to military force, mutual intimidation, and the parading of stockpiles of arms,” Francis said.

The world cannot but be “genuinely concerned” by the “catastrophic humanitarian and environmental effects,” of deploying nuclear devices, taking into account also the possibility of an accidental detonation. The threat of their use, as well as their existence, has to be “firmly condemned.”

Francis’s words came as he was addressing participants in an International Symposium called “Prospects for a World Free from Nuclear Weapons and for Integral Disarmament,” organized by the Vatican’s Dicastery for Promoting Integral Human Development.

The Nov. 10-11 gathering was requested by Francis, and wasn’t intended to coincide with President Donald Trump’s visit to Asia, however, as Cardinal Peter Turkson of Ghana said, it was “providence.”

Eleven Nobel Peace laureates, UN and Nato officials and a handful of nuclear powers including Russia, the United States, South Korea and Iran, are among participants in the symposium, that wants to garner momentum towards a shift from the Cold War era policy of deterrence to one of total nuclear disarmament.

Nuclear weapons, Francis said on Friday, “exist in the service of a mentality of fear that affects not only the parties in conflict, but the entire human race.”

As speakers said throughout the first morning, mutually assured destruction does not bring about peace, but puts the world on the brink of a nuclear holocaust.

Weapons of mass destruction, Francis insisted, can’t be the basis for peaceful coexistence. Instead, he said, an ethics of solidarity should be the cornerstone for it.

According to the 2017 Nobel Peace awardees ICAN (International Campaign to Abolish Nuclear Weapons), nine countries together possess around 15,000 nuclear weapons. The United States and Russia maintain roughly 1,800 of their nuclear weapons on high-alert status – ready to be launched within minutes of a warning. Most are many times more powerful than the atomic bombs dropped on Japan in 1945.

ICAN was represented at the conference by executive director Beatrice Fihn, who told journalists that “we built these weapons, we can tear them apart. We have to stop letting these weapons control us, we control them.”

During his remarks, Francis also noted that weapons that can lead to the destruction of the human race are “senseless even from a tactical standpoint,” and that even though “true science” is at the service of humanity, “we are increasingly troubled by the misuse of certain projects originally conceived for a good cause.”

Furthermore, the pope said, nuclear technologies are now spreading, and international law has not prevented new states from joining those already in possession of nuclear weapons.

“The resulting scenarios are deeply disturbing if we consider the challenges of contemporary geopolitics, like terrorism or asymmetric warfare,” he added.

However, despite the reasons Francis listed for pessimism, a healthy dose of realism continues to “shine a light of hope” in the world. As an example, he quoted a recent vote at the United Nations, where the majority of the members of the international community decided that nuclear weapons are “immoral” and must be taken as “an illegal means of warfare.”

The Treaty on the Prohibition of Nuclear Weapons– adopted on 7 July this year at a UN conference in New York by a vote of 122 in favor to one against (Netherlands), with one abstention (Singapore) – prohibits a full range of nuclear-weapon-related activities, such as undertaking to develop, test, produce, manufacture, acquire, possess or stockpile nuclear weapons or other nuclear explosive devices, as well as the use or threat of use of these weapons.

Though it was praised by many participants in the Vatican conference, many of the major players in the world’s nuclear standoff, including the United States, the United Kingdom and France didn’t take part in the negotiations. Furthermore, they have released a joint statement saying that they “do not intend to sign, ratify or ever become party to it.”

Many of the non-nuclear-armed members of the North Atlantic Treaty Organization (NATO), including Germany, Italy, Turkey and Poland, along with Australia and Japan, have voiced resistance to the ban treaty, as they believe that U.S. nuclear weapons enhance their security.

Yet according to Francis, the treaty filled a “significant juridical lacuna, inasmuch as chemical weapons, biological weapons, anti-human mines and cluster bombs are all expressly prohibited by international conventions.”

Even more important, he considered, is the fact that the treaty was put forth as the result of a “humanitarian initiative” sponsored by an alliance between civil society, states, international organizations, churches and experts.

To achieve the “utopia” of a world free of “deadly instruments of aggression,” he said, three things are needed: the rejection of the culture of waste and favoring processes of solidarity over selfish interests; integrating the individual and social dimensions through subsidiarity; and the promotion of the person “in the indissoluble unity of soul and body.”

Francis closed by quoting St. Pope John XIII, from his 1963 encyclical letter Pacem in Terris: ““Unless this process of disarmament be thoroughgoing and complete, and reach men’s very souls, it is impossible to stop the arms race, or to reduce armaments, or – and this is the main thing – ultimately to abolish them entirely.”