because of the particular situation.

Going to see the scene of the explosion was, under the circumstances, a really stupid thing to do.

The storm was very dangerous, so under the circumstances I think we were lucky to have had only one tree blown down.

Usage notes: also used in the form under those circumstances:

There is an ongoing investigation, and under those circumstances, it wouldn't be right for me to comment.

• when someone's back is turned
• when someone sneezes, someone catches a cold
• when someone sneezes, something catches a cold
• when someone was a mere twinkle in father's eye
• when someone was a mere twinkle in their father's eye
• when someone was a twinkle in father's eye
• when someone was a twinkle in their father's eye
• when something sneezes, someone catches a cold
• when something sneezes, something catches a cold
• When the cat's away .
• When the cat's away the mice will play.
• when the chips are down
• when the dust settles
• when the going gets rough
• when the going gets tough
• when the spirit moves
• when the spirit moves you
• when was a mere twinkle in father's eye
• when was a mere twinkle in their father's eye
• when was a twinkle in father's eye
• when was a twinkle in their father's eye
• when your ship comes in
• where is coming from
• where someone is coming from
• Where's the beef?