{{#evt: | service= youtube | id= SMJK0w2Pkng | description= Victoria 3: November 2021 Update. A summary of last month's dev diaries, including: Rank and Prestige, Relations, Infamy and Interests, Diplomatic Actions, and Diplomatic Plays. | alignment= right | container=frame }}
采取外交行动是一个国家进行外交的重要手段，例如改善/破坏关系、签署各种协议。外交行动是由一国发起的目标为另一国的互动，有些外交行动需要目标国的同意才能生效。
外交行动类型
所有的外交行动可被分为三种类型：
- 即时行动：这类外交行动将会在目标国同意之后立刻生效（如果需要同意的话）。因为其是即时完成的，因此该类别的行动不需要任何影响力来维护。
- 持续性行动：这类外交行动是发起国对目标国的持续性行动，且只能由发起国取消。由于其持续性，此类行动的发起国需要消耗影响力来维持其外交行动，行动的目标国则不需付出任何影响力。
- 条约：这类行动指那些只要双方同意就可持续维持下去的各种协议。如果需要影响力进行维护，则双方都需要支付其影响力，除非该条约规定了明确的主从关系（如宗主国需要付出影响力维持与其附属国的附属关系）。条约的双方均可取消此项条约，但往往需要另一方的统一。
开展外交行动的条件纷繁复杂，开展不同的行动往往需要先满足各种前提条件。
即时行动
该类别的外交行动包括：
- 驱逐外交官：这一行动将会立刻降低 30 点两国之间的关系，且终止两国间正在进行的所有改善关系行动。在执行该行动的 5年 内双方也无法进行新的改善关系行动。该行动的发起方将因此受到 10 恶名惩罚，且无法在 5年 内再次驱逐同一个国家的外交官。
- 承担债务：这一行动将使得发起国支付目标国当前的所有债务，如果目标国同意则将欠发起国一个义务。
- 免除义务：这一行动将使得发起国通过移除目标国对其的一个义务（前提是拥有义务），以立刻提升 30 点两国之间的关系。
- 侵犯主权：这一外交行动将使得发起国侵犯目标国的中立，并要求其提供军事通行权，发起这一行动将会引发外交事件。
持续性行动
该类别的行动包括：
- 改善关系：这一行动将使得发起国持续改善与目标国之间的关系，每日的基础速率为 3%，这项行动最多能将两国之间的关系改善到 +50。发起国需要花费影响力来维持该行动，基础维护费为 150，如果目标的国家地位更高将花费额外的影响力。
- 破坏关系： 这一行动将使得发起国持续破坏与目标国之间的关系，每日的基础速率为 3%，这项行动最多能将两国之间的关系降低到 -50。发起国需要花费影响力来维持该行动，基础维护费为 100，如果目标的国家地位更高将花费额外的影响力。
- 资助：这一行动将使得发起国持续以每周为单位支付其目标国收入的 20% 给目标国以援助其财政。这一行动也将使得发起国持续改善与目标国之间的关系，每日的基础速率为 3%，这项行动最多能将两国之间的关系改善到 +80。发起国需要花费影响力来维持该行动，基础维护费为 100。 在该行动进行期间，发起国每周都有 1% 的概率获得目标国的义务。
条约
Some example actions in these categories are:
Non-Subject Pacts
- Alliance: This is a diplomatic pact that allows two countries to help each other when attacked in a Diplomatic Play, even if they do not have an Interest in the relevant area (more on this next week). Costs Influence to maintain, with the cost increasing if the other part has a high Rank.
- Customs Union: This is a diplomatic pact where there is a senior and a junior partner, and makes the junior partner part of the senior partner's national market instead of having their own market. Costs Influence to maintain for the senior partner only, with the cost increasing if the other part has a high Rank.
- Trade Agreement: This is a diplomatic pact which gives both countries competitive advantages when establishing trade routes in the market of the other country. Costs Influence to maintain, with the cost increasing if the other part has a high Rank.
Subject Pacts
- Protectorate: This is a type of non-colonial subject relationship where the subject is very autonomous, the only restriction placed on them being that they are not able to have a fully independent foreign policy. Can be turned into a Puppet by their overlord through a Diplomatic Play.
- Puppet: This is a type of non-colonial subject relationship where the subject has no diplomatic autonomy, pays part of their income to their overlord and is part of the overlord's national market. Can be annexed by their overlord through a Diplomatic Play.
- Dominion: This is a type of colonial subject relationship where the subject has extensive diplomatic autonomy and can have their own subjects, though they're still required to be part of their overlord's market. Can be turned into a Territory by their overlord through a Diplomatic Play.
- Territory: This is a type of colonial subject relationship where the subject has limited diplomatic autonomy, pays part of their income to their overlord and is part of the overlord's national market. Can be annexed by their overlord through a Diplomatic Play.
- Tributary: This is a special subject relationship only available to Unrecognized Powers where the subject has extensive diplomatic autonomy and can have their own subjects, though they're required to pay part of their income to their overlord. Can be turned into a Vassal by their overlord through a Diplomatic Play.
- Vassal: This is a special subject relationship only available to Unrecognized Powers where the subject has no diplomatic autonomy, pays part of their income to their overlord and is part of the overlord's national market. Can be annexed by their overlord through a Diplomatic Play.