This would be against diplomatic etiquette.是什么意思？

This would be against diplomatic etiquette.

这将在外交上犯失礼的错误.

this

pron. 这，这个，这事，这人，这时，下面所说的事；adj. 这，这个，刚过去的，即将到来的，今…，本…；adv. 这样地，就是这样，这么地；

例句
Victoria Falls has had above average levels of rainfall this year...
维多利亚瀑布今年的降雨量超过了平均水平。

would

aux. 将，将要，愿意，会，打算，大概；v. (will 的过去式，用于转述)将；

例句
I would love to go abroad this year, perhaps to the South of France.
我今年很想出国，可能是去法国南部。

be

v. 是，有，存在，做，成为，发生；aux. 用来表示某人或某物即主语本身，用来表示某人或某物属于某一群体或有某种性质；

例句
The older child should be able to prepare a simple meal...
那个年纪稍大的孩子应当会做一顿简单的饭菜。

against

prep. 反对，对…不利，紧靠，以防；

例句
His hand brushed against hers; it could have been either accidental or deliberate.
就在有意无意间，他的手轻轻拂过她的手。

diplomatic

adj. 外交上的，外交人员的，有手腕的，策略的；

例句
The President has played a shrewd diplomatic game because from the outset he called for direct talks with the United States...
总统玩了一场高明的外交游戏，因为从一开始他就要求和美国直接对话。

etiquette

n. 礼仪，礼节，规矩，礼数；

例句
The rules of etiquette are not so strict nowadays.
如今的礼仪规则已不那么严格了。