The phrase 'a lack of caution' is correct and usable in written English.
You can use it to indicate when someone is not taking enough care, or is being too daring in a risky situation. For example: "She acted with a lack of caution and ended up getting into a dangerous situation."
"The prime minister's amazing statement regarding nuclear capability indicates a lack of caution bordering on irresponsibility," the Yedioth Ahronoth newspaper quoted him as saying.
Palpable in these three courtships (all of which broke off shortly thereafter) is a lack of caution, and perhaps of empathy, on the part of the overeager lover.
Speaking at Team USA's London 2012 media summit in Dallas, Merritt blamed a lack of "caution" for his very public ordeal.
A columnist for the Washington Examiner scolded the media for a lack of caution and said that liberal commenters should have been more skeptical of the story because "too many such incidents have turned out to be hoaxes".
So as he began to use drugs, he did so with a recklessness and a lack of caution for his own safety that was alarming to everyone who knew him.
Some art historians believe that this situation has fostered a lack of caution in connecting works with historical persons, and that such connections often rest on tenuous circumstantial evidence.
"We're not going to win a hockey game tonight, 1-0," Coach John Tortorella, worried about a lack of scoring, cautioned before the game.
It is simply another subversive spectacle, the subversion of which consists at least partly in its semi-seriousness: the sheer insolence of treating the subject of slavery with a jokey lack of caution.
But Tam's lack of caution gives a kind of authority to his denial that Ravi was homophobic.
Fitt's strengths were his gregarious ability to talk, drink and empathise across any divide, and his lack of caution when he felt an injustice threatened.
Millions of Americans are receiving auto loans they cannot possibly afford, in a lending climate marked by some of the same lack of caution seen in the housing industry before its 2008 implosion.
