They say we are at war.

What does war look like?

Our enemy is violent Islamic extremism. He is Daesh. He is al-Qaeda. The enemy consists of all groups and adherents of violent Islamic extremism. Our enemy is the “global jihad” movement inspired by the 9/11 attack. They seek to impose an aberrant ideology on the world. For Daesh and their allies, coexistence with their enemies is unimaginable. Compromise is impossible. Daesh has adopted the mindset of an apocalyptic cult group. For Daesh, the Quranic End of Days has already begun. The battle of all battles looms — Armageddon in Dabiq, Syria. Daesh is not a rational actor in the western tradition. Their actions cannot be fully understood the application of western logic and reason. Our enemy believes they are in an existential struggle to destroy the civilized world and our way of life.

To adopt the right mindset for confronting such an enemy, we should draw on the lessons of World War II. The greatest generation united in the noble cause of eliminating the evil of fascism. Fascism could not be contained; it had to be destroyed. We face a similar moral choice today. This is a battle between good and evil. The world must not rest until Daesh and the false caliphate is destroyed. The world must rescue millions of Syrians from the injustice and desperation of their circumstances. We cannot declare victory until the fire of violent Islamic extremism is extinguished from the earth.

That is why this is a war.

A successful strategy to win the war consists of a basic four step process:

1) Building and deploying a multinational coalition army to occupy Syria and destroy the Daesh and dismantle the group’s so-called state, on an internationally recognized legal basis;

2) Establishment of a global coalition of intelligence and law enforcement services to neutralize the militants’ “global jihad”;

3) Implementation of the roadmap for a political settlement in Syria that Secretary of State John Kerry laid out in principle in Paris; and

4) A long term plan to win the peace: Resolve the Syrian refugee and human rights crisis, implement a Marshall-like plan to rebuild a shattered region, and address the underlying causes of the conflict.

I would like to focus only on the first two steps, because they must be accomplished before it will be possible to implement the last two steps of the process.

To play its right role in winning this war, the US must acknowledge what this “war” entails: Without boots on the ground, nothing changes. A ground invasion of overwhelming force is required to destroy the so-called caliphate and eliminate Daesh as a threat. The Arab states must lead the multinational coalition that must be formed, including the US, western European countries, Russia, and its allies.

Preparation for introducing ground forces should not be considered to be complete until the coalition has the full and balanced participation of all states opposed to Daesh, and not until they are willing to commit sufficient combat troops to constitute an overwhelming force.

The prospect of assembling such a grand coalition is dim, at present. The enemies of Daesh are working piecemeal, and limiting their level of commitment in confronting Daesh. However, half-measures will not eliminate this threat. Using air power alone will not be sufficient to eliminate Daesh and its allies. Limiting the military option largely to airstrikes has failed to contain Daesh’s ability to mount terrorist strikes outside Syria, as recent attacks in Sharm el-Sheikh, Beirut, and Paris have conclusively shown.

The wave of Daesh terrorism has not crested. The world must be prepared for more attacks that are on the way. Given time, Daesh will continue to expand its capability and sophistication in conducting terrorist attacks. The Syrian refugee and human rights crisis will continue to grow unabated, as the world ignores the systematic slaughter of innocent civilians — and as refugees show up on our shores in large numbers.

US statements of expanding intelligence cooperation and provision of information to France to the full extent of US law should be welcomed, but they raise a question: Was the US already providing such information before the Paris attack? Hopefully, the French were receiving any and all information available to the US intelligence community. Sharing threat information broadly and quickly throughout the world should be driven by the “duty to warn” principle:

An intelligence community element that collects or acquires credible and specific information indicating an impending threat of intentional killing, serious bodily injury, or kidnapping directed at a person or group of people (hereafter referred to as intended victim) shall have a duty to warn the intended victim or those responsible for protecting the intended victim, as appropriate. This includes threats where the target is an institution, place of business, structure, or location. The term intended victim includes both U.S. persons, as defined in EO 12333, Section 3.5(k), and non-U.S. persons.

Americans are weary of war. Americans know first-hand the price of waging war. I am not an advocate of war; it should be a means of last resort. This war has been thrust on us by the scourge of barbarism and terrorism. The US must fight to defend itself and uphold the universal values that all nations of the civilized world hold dear — life, liberty, human rights, to live free from terror. In so doing, the US must be careful not to get out in front of the states in the conflict zone with the most at stake. The US should play its role to support the people who reside in the region to reclaim their lands, with the understanding we are helping them win their war. The coalition of nations against Daesh and violent Islamic extremism must strike a decisive blow as soon as possible. The longer the world waits to launch full-scale military campaign against Daesh, the higher price the world will pay.