Hearts of Iron 4 (HOI4) – Best Air Doctrine

Debates over doctrines are a common occurrence in Heart of Iron 4, with players fervently arguing over which one is the most beneficial. With only one doctrine to choose out of 3 or 4 options, the decision can be contentious.

Typically, the best answer is to select the doctrine that best fits your needs. This is especially true for air doctrines, where the bonuses are generally favorable, unlike land doctrines where Mass Assault should be avoided at all costs.

To make the right choice, consider where you are willing to be weaker and what you hope to gain from utilizing your air force.

In this guide, we will delve into the various air doctrines in Hearts of Iron 4, explaining the benefits of each and why, more often than not, Operational Integrity emerges as the top choice.

What Each Air Doctrine Does

Hearts of Iron 4 offers three air doctrines to choose from:

  • Strategic Destruction
  • Battlefield Support
  • Operational Integrity

While all doctrines provide similar bonuses, there are a few unique bonuses that can make a significant impact.

Here are the common bonuses you will receive regardless of the doctrine you pursue:

  • Air Superiority: +15%
  • Fighter Detection: +10%
  • Ground Support: +10%
  • Interception Detection: +10%
  • Naval Mission Efficiency: +10%

Strategic Destruction

Strategic Destruction is the go-to doctrine for players looking to decimate their enemies’ provinces using Strategic Bombers.

This branch presents choices between improving Fighter skills in Interception or Air Superiority missions, as well as selecting between a significant flat bonus to Strat Bombing or a smaller bonus with reduced night debuff.

For those focused on bombing enemies relentlessly, Strategic Destruction is the optimal doctrine.

Aside from the common bonuses listed earlier, here are the exclusive bonuses from this doctrine:

  • Air Superiority: +15%
  • Bomber Defense: +25%
  • Escort Efficiency: +25% & Strategic Bombing: +50% / +40% & Night Time Strategic Bombing Penalty: -50%
  • Fighter Agility: +10%
  • Interception Mission Efficiency: +20% / Air Superiority Mission Efficiency: +20%
  • Naval Mission Efficiency: +5%

Battlefield Support

Battlefield Support aims to enhance Close Air Support (CAS) and inflict significant damage on land troops beneath the air force. While the description suggests substantial damage, the actual impact may not be as significant.

Despite this, Battlefield Support can provide an edge in ground battles, especially when paired with Air Superiority.

Here are the bonuses specific to this doctrine:

  • Air Superiority: +15%
  • Air Superiority Mission Efficiency: +15% / Ace Generation Chance: + 25%
  • Air Support Mission Efficiency: +40%
  • CAS Agility: +20%
  • Fighter Detection: +5%
  • Ground Support: +30%
  • Interception Detection: +5%
  • Strategic Bombing: +15%
  • Tactical Bomber Strategic Bombing: +10%

Operational Integrity

Although described as the tactical bomber doctrine, Operational Integrity is actually best suited for fighters. The key to winning aerial battles and achieving Air Supremacy lies in making your fighters superior to the enemy’s.

Operational Integrity equips you with the necessary tools to dominate the skies and secure Air Supremacy, a crucial aspect for delivering devastating CAS damage.

Exclusive bonuses from this doctrine include:

  • Ace Generation Chance: +20%
  • Air Superiority Mission Efficiency: +20%
  • Bomber Defense: +20%
  • Fighter Agility: +10%
  • Fighter Detection: +10%
  • Interception Detection: +10%
  • Interception Mission Efficiency: +20%
  • Strategic Bombing Visibility: -50%
  • Tactical Bomber Strategic Bombing: +20%

What Everything Means

Understanding the bonuses associated with each doctrine is crucial in making an informed decision:

  • Ace Generation Chance: Increase the likelihood of generating aces during missions.
  • Air Superiority Mission Efficiency: Enhances air attack, air defense, and agility for planes on this mission.
  • Air Support Mission Efficiency: Improves air attack, air defense, and agility for planes on this mission.
  • Bomber Defense: Boosts air defense for planes on Strategic Bombing mission.
  • Enemy Air Support: Adjusts the impact of enemy air superiority on our ground troops’ combat ability.
  • Escort Efficiency: Minimizes disruption from enemy attacks.
  • Fighter Detection: Augments the detection planes on Air Superiority mission contribute to the region.
  • Ground Support: Amplifies the scaling rate of the Enemy Air Support bonus provided by air superiority.
  • Interception Detection: Increases the contribution of detection planes on Interception mission to the region.
  • Interception Mission Efficiency: Enhances air attack, air defense, and agility for planes on this mission.
  • Naval Mission Efficiency: Improves air attack, air defense, and agility for planes on this mission.
  • Night-time strategic bombing penalty: Mitigates the adverse effects of night for planes on Strategic Bombing mission.
  • Strategic Bombing Visibility: Counters enemy detection during Strategic Bombing mission, reducing the maximum number of enemy planes responding to the bombers.
  • Strategic Bombing: Increases Strategic Bombing damage for planes on that mission.

What Is the Best Air Doctrine in Hearts of Iron 4?

Operational Integrity emerges as the top choice for most countries in Hearts of Iron 4, serving as the best air doctrine overall.

Success in air battles often hinges on losing fewer fighters than your opponent. Operational Integrity excels in this regard, making it ideal for minor countries seeking to secure Air Supremacy.

By selecting Operational Integrity, players can focus on protecting their skies and gaining an advantage in aerial combat, crucial for preventing devastating CAS damage or disruptive bombing.

In a comparative video by 71Cloak, Operational Integrity consistently outperformed the other doctrines, losing fewer fighters in battles and asserting dominance in Air Superiority.

Which Countries Should Choose Strategic Destruction

While Operational Integrity is favored by most countries, Strategic Destruction may be the preferred choice for nations with extensive production capabilities that can afford losses in air battles.

Countries like the United Kingdom and the USA, with robust industrial capacities, are recommended to complete the Strategic Destruction doctrine to disrupt enemy industries effectively.

In particular, Commonwealth nations can benefit from Strategic Destruction by conducting strategic bombing campaigns to destabilize enemy territories without direct involvement in ground combat.

Which Countries Should Choose Battlefield Support

Countries engaged in large-scale land battles, such as Germany, the USSR, and Japan, may find Battlefield Support advantageous for bolstering ground offensives.

Despite the risk of losing more planes, Battlefield Support can provide the edge needed to triumph in land conflicts, especially when supported by a strong fighter design.

The focus on inflicting damage on ground troops complements the goal of securing Air Superiority, making Battlefield Support valuable for nations prioritizing land engagements.

Here are the recommended air doctrines for each country in Hearts of Iron 4:

  • Afghanistan: Operational Integrity
  • Albania: Operational Integrity
  • Argentina: Operational Integrity
  • Sultanate of Aussa: Operational Integrity

That concludes our detailed analysis of the best air doctrines in Hearts of Iron 4!

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