The most common and most likely answer to this crossword clue is the 9 letter word DIPLOMACY
I've seen this crossword clue in The Guardian
D
I
P
L
O
M
A
C
Y
More clues leading to the result DIPLOMACY
- Tact of detective, quick to accept large award
- Maybe I’d comply with American premier’s tactfulness
- Qualification on the boundaries of clarity and tact
- International relations destabilising Olympic day endlessly
- Tactful approach revised mad policy
- 6 Carry empty certificate, going up with tact
- Decline honour in delicate art of discretion
Buddy explains!

The straight part
We know that "tact" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tact = diplomacy.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DIPLOMACY mean?
DIPLOMACY noun- The art and practice of conducting international relations by negotiating alliances, treaties, agreements etc., bilaterally or multilaterally, between states and sometimes international organizations, or even between polities with varying status, such as those of monarchs and their princely vassals.
- Tact and subtle skill in dealing with people so as to avoid or settle hostility.