Classified U.S. Intelligence Report:
“War Is Unlikely to Bring Down Iran’s Regime”

A classified U.S. intelligence report has been leaked.

Its conclusion is simple, but deeply significant.

“Even war is unlikely to bring down Iran’s regime.”

This report was a classified document produced by the National Intelligence Council (NIC), which integrates analysis from across the U.S. intelligence community.

Its contents were reported by The Washington Post.

The NIC is an organization that synthesizes analysis from 18 U.S. intelligence agencies, including the CIA, and its assessments are widely regarded as the closest reflection of the U.S. intelligence community’s overall judgment.

The report analyzed scenarios in which the United States would launch a large-scale military attack on Iran.

But its conclusion was clear.

A military assault is unlikely to destroy Iran’s clerical-military system.

U.S. Intelligence Assessment: Even Military Strikes Are Unlikely to Collapse the Regime

The report examined multiple military scenarios, ranging from limited attacks aimed at the leadership to large-scale strikes designed to destroy government institutions across a broad area.

More specifically, it considered cases such as:

• a “decapitation strike” targeting the supreme leader or senior military commanders
• large-scale airstrikes aimed at the Islamic Revolutionary Guard Corps and government institutions
• combined operations targeting both the leadership and military facilities at the same time

Yet according to the U.S. intelligence assessment, none of these scenarios is likely to bring down Iran’s regime.

One reason is that Iran’s power structure is sustained not by a single individual, but by institutions.

Even if the supreme leader or part of the leadership were removed, the regime would likely endure as long as the following power structures remained in place:

• the clerical network
• the Islamic Revolutionary Guard Corps
• the state security apparatus

In addition, external military attacks are also known to weaken domestic political divisions and often strengthen national cohesion.

As a result, outside attacks may not weaken the regime. On the contrary, they may actually strengthen the influence of hard-liners.

Even If the Leader Is Killed, the System Would Likely Endure

A Decapitation Strike Would Not Collapse the Regime

Even if Iran’s Supreme Leader Ali Khamenei were killed, analysts believe Iran’s clerical and military elites would preserve continuity of power through an institutionalized succession process.

This is because power in Iran is not concentrated in a single individual alone. It is supported by multiple power centers, including religious institutions, the military, and the security apparatus.

For that reason, even if the supreme leader were removed, the state itself would not be likely to collapse immediately.

Historically as well, when leaders are killed by outside attacks, the result is often not regime breakdown but stronger internal cohesion and increased influence for hard-liners.

In other words, the simple scenario in which a so-called “decapitation strike” causes the regime to collapse is not seen as realistic in Iran’s case.

There Is an Institutional Mechanism for Choosing a Successor

Iran has an established system for selecting the successor to the supreme leader.

The central body in that process is the Assembly of Experts, a council made up of clerics.

This body has the authority to choose the supreme leader, and if the current leader dies, it is expected to select a new one.

In practice, however, the real power structure also includes major influence from the Islamic Revolutionary Guard Corps and national security institutions, meaning that political and military elites are deeply involved in preserving the system.

Because such institutional arrangements exist, the removal of one individual does not automatically lead to the collapse of the state.

Iran’s Opposition Is Unlikely to Take Power

The Opposition Is Fragmented

In Western discussions, it is often assumed that if the regime collapses, democratic forces will naturally rise in its place.

But the U.S. intelligence assessment is far more cautious. Iran’s opposition is not a unified bloc. It is divided among exile groups, domestic reformists, ethnic minority movements, and elements dissatisfied from within the system, and their political positions and visions for the country differ sharply.

Some favor a restoration of monarchy, others seek a secular republic, and still others place greater emphasis on ethnic autonomy or even separation. In other words, they may share opposition to the current regime, but they do not agree on what kind of state should come next.

For that reason, even if the current system were weakened, it is difficult to assume that the opposition would quickly unite and build a new government.

On the contrary, if a power vacuum emerged after regime weakening or collapse, rivalries over leadership and disputes over political direction could surface among opposition forces themselves, deepening instability rather than resolving it.

This is a pattern seen in many countries: groups may cooperate while they share a common enemy, but once that enemy weakens, internal divisions often intensify.

The Problem of Governing a State

An even greater problem is that Iran’s opposition does not appear to possess the institutional foundation or organizational capacity needed to govern the country in a stable way.

Running a state requires layered and continuous capabilities: control over the military and bureaucracy, maintenance of public order, economic management, local administration, infrastructure management, and foreign policy coordination.

But the current Iranian opposition lacks a unified leadership and political base capable of carrying all of these functions together.

Exile groups may have voices abroad, but they do not actually control Iran’s domestic administrative machinery or security institutions. Conversely, even if many people inside the country are dissatisfied, that does not automatically translate into nationwide governing capacity.

The most difficult moment comes immediately after state authority begins to break down. That is precisely when the highest degree of governing ability is required. Food and energy supply, public order, continuity of local administration, and the prevention of reprisals and vigilante violence cannot be paused even for a single day.

If the regime were to collapse without a force prepared to take over those tasks, the result would likely not be democratization, but a power vacuum, worsening disorder, and possible regional fragmentation.

The reason U.S. intelligence agencies judge an opposition takeover to be “unlikely” is not simply a matter of popularity or support. It is rooted in the opposition’s lack of practical capacity to run a state.

Opposing a regime and being able to govern a country are entirely different things.

Why Iran’s System Is Difficult to Overthrow

A State Structure Where Religion and Politics Are Intertwined

In Iran, a political system has been built over many years in which the religious leadership, the military, and the security apparatus are tightly intertwined.

This cannot be reduced to the simple label of a “religious state.” Iran’s system is sustained by an overlapping structure of religious legitimacy, state bureaucracy, security institutions, and the political ideology formed after the revolution.

As a result, while it may look from the outside like a rigid hierarchy centered on a single supreme leader, in reality it is a structure in which multiple institutions and organizations support one another.

For example, the religious leadership does not function merely as a symbol; it serves as a source of political legitimacy. At the same time, the state bureaucracy handles day-to-day administration, and the security apparatus supports the practical work of preserving the system.

In other words, the system does not rest on one charismatic individual or a single institution. It is upheld by a layered state structure in which religion, politics, and security overlap.

In such a system, even if outside military strikes eliminate some leaders or destroy certain facilities, that does not necessarily mean the state as a whole will collapse all at once.

On the contrary, the appearance of an external enemy can temporarily push domestic discontent and internal divisions into the background, while reinforcing the regime’s legitimacy through the logic of “national defense.”

In Iran, anti-U.S. and anti-foreign-pressure narratives are closely tied to the regime’s self-justification, so outside attacks are not merely military pressure. For the regime, they can also become political resources that encourage internal cohesion.

That is why, even if an attack looks like a “major blow” from the outside, it does not necessarily translate into regime collapse from within.

The Strong Influence of the Islamic Revolutionary Guard Corps

The Islamic Revolutionary Guard Corps (IRGC), in particular, is an extremely important pillar of Iran’s system.

The IRGC is not merely a military organization. It possesses armed force, but it is also deeply involved in politics, the economy, security, and foreign operations, and is embedded in the core of the state.

For that reason, even if outside forces strike military facilities, it would be difficult to remove the IRGC’s influence itself in a single blow.

Moreover, the IRGC defines its own mission as the defense of the system, so the stronger outside pressure becomes, the more its role and influence may actually expand.

This is different from the military in an ordinary nation-state. The IRGC is not only a force that “defends the country,” but also an organization that protects the regime itself.

In addition, because its influence penetrates politics and the economy, even if it suffers military losses, that does not mean the state as a whole immediately loses its capacity to function.

Because of this structure, outside attacks in Iran do not easily translate into the collapse of the regime itself.

On the contrary, as pressure intensifies, hard-line organizations such as the IRGC are more likely to move to the forefront as “defenders of the nation.”

This is one of the major reasons Iran’s system has such strong staying power.

Differences of Opinion Inside the United States

The Intelligence Community’s Assessment

What makes this report especially interesting is that it highlights a clear difference in perception within the U.S. government.

The intelligence assessment is straightforward: “Even war is unlikely to bring down Iran’s regime.”

And this is not presented as the view of only a few individuals. It is described as an assessment compiled by the National Intelligence Council (NIC). The NIC occupies a position that integrates analysis from multiple U.S. intelligence agencies, and its reports become one of the important reference points in Washington’s policymaking.

In other words, this classified report does not merely suggest that “some people are cautious.” It indicates that within the U.S. intelligence community, a large-scale attack on Iran is not generally seen as something that would automatically lead to regime collapse.

The role of intelligence is, by nature, to assess reality rather than desire. It examines the structure of the target state, its social organization, succession mechanisms, and the resilience of its military and security institutions, and then estimates as coolly as possible what kind of political results war is actually likely to produce.

From that perspective, even if Iran were to suffer major military damage, that would not necessarily mean the regime would collapse immediately. Rather, it could lead to prolonged conflict and broader regional instability. That appears to be the realistic conclusion reached by the intelligence community.

The key point here is that military success and political success are not the same thing.

It may be possible to destroy an enemy’s facilities, but that does not mean the desired new government can be created as a result. This report makes that gap unusually clear.

The Political Decision

At the same time, however, the Trump administration has continued to make statements suggesting the removal of Iran’s leadership and the establishment of a new government—that is, a form of regime change.

In other words, the intelligence community is skeptical about the effectiveness of war, while politics is moving ahead with military action anyway.

This gap is not accidental. Political decisions are not determined by intelligence analysis alone. They are shaped by many factors, including domestic public opinion, relations with allies, the governing coalition’s search for political momentum, ideology, military prestige, and electoral calculations.

War in particular is often tied less to “what it will realistically achieve” than to political theater—whether leaders appear strong, whether they seem to be in control, and whether they can project an image of decisive action.

For that reason, even when intelligence agencies present a cautious assessment, political leaders may still choose a more aggressive course.

This is not unusual in U.S. politics. During the Iraq War, for example, parts of the intelligence community raised doubts about the existence of weapons of mass destruction, yet war was ultimately carried out as a political decision.

And the result was that even if the military campaign itself succeeded, the attempt to govern and stabilize the region afterward produced enormous disorder. It was a classic example of military victory and political success failing to align.

In the current Iran situation, the same problem appears to be resurfacing.

The intelligence community is asking what that war can actually accomplish, while politics is constructing reasons to wage it on a different plane.

That difference is one of the most important points in this report.

Implications for Japan

Military Power Alone Does Not Solve the Problem

This report also carries important implications for Japan’s security debate.

In Japan, the word “realism” has in recent years been used more and more frequently in discussions of national security.

And that “realism” is often invoked to justify military expansion, stronger deterrence, and tighter military alliances.

Yet the latest U.S. intelligence assessment shows that real war is not nearly that simple.

Even when a state with overwhelming military power launches an attack, it does not necessarily follow that the other side’s regime will collapse.

On the contrary, the attacked state may become more cohesive, hard-liners may gain influence, and the region may become unstable for the long term.

This has serious implications for Japan’s own security debate. In part of Japan’s security discourse, it is often assumed that the more military power one accumulates, the easier it becomes to control events.

But in real international politics, military force is not an all-purpose tool that automatically compels the other side to submit. As long as a country’s political system, history, religion, nationalism, and social structure are deeply intertwined, applying more outside pressure can sometimes strengthen resistance and internal cohesion instead.

In other words, increasing military pressure is not the same thing as achieving politically desirable results.

This report shows exactly that. War is often described as a “solution,” but in reality it often prolongs problems in a different form.

The Reality of Security Policy

Iraq, Libya, and Syria are clear examples of this pattern.

Even when military intervention weakened an existing regime, it did not necessarily produce a stable political order afterward. Instead, it often triggered a chain of consequences: power vacuums, worsening public order, civil conflict, refugee outflows, and wider regional instability.

This report suggests that military power is far from omnipotent, despite what some versions of “realist security policy” in Japan tend to assume.

What truly matters for Japan is not simply discussing military capability in the abstract, but deciding what kind of regional order it wants to preserve, and how diplomacy, economic policy, and international cooperation should be combined to support that goal.

Japan depends heavily on energy supplies from the Middle East, and prolonged instability in that region directly affects the Japanese economy. If so, Japan’s national interest lies not in the expansion of war, but in the containment of tensions and the stability of shipping lanes and energy supplies.

If security policy is discussed only in terms of how far Japan should align itself with the United States, Japan risks losing sight of its own reality.

Real realism does not mean simply siding with the stronger power. It means coolly identifying Japan’s own national interest and the conditions for regional stability.

In that sense, this U.S. intelligence assessment poses an important question for Japan as well.

Building up military power and creating security are not the same thing.

The Reality of International Politics

International politics is often not determined by military power alone.

Religion, ethnicity, political systems, domestic circumstances, historical memory, and relations with neighboring countries are all intertwined in complex ways.

For that reason, even a state with overwhelming military superiority cannot necessarily move another society or political system exactly as it wishes.

It may be able to destroy facilities, remove leaders, and inflict major military damage, but that does not mean it can create a stable political order afterward.

This classified U.S. intelligence report underscores that reality once again.

War is often described as a “solution.”

But in practice, it more often hardens regimes rather than toppling them, creates power vacuums rather than democracy, and spreads prolonged disorder rather than stability.

As the cases of Iraq, Libya, and Syria show, the hardest part of military intervention is often not how to begin it, but how to end it.

And the heaviest price is almost always paid by ordinary civilians on the ground.

I am deeply uneasy when Japan fails to face that reality and instead justifies military expansion merely through words like “realism” and “deterrence.”

Real realism does not mean following the stronger side.

It means coolly asking what war actually brings, and what is truly most realistic for Japan’s national interest and for regional stability.

In that sense, this report poses a serious question for Japan as well.

Expanding military power is not the same thing as creating peace and stability.

The future course of the Middle East may once again make that painfully clear.