First-order thinking judges a decision by the result it was made to produce: the deal lands or the backlog shrinks. Second-order thinking asks what that result sets off next, in the people, cash and time around it. The first result is the one you planned for, so it's the one you check.
The sociologist Robert Merton mapped this gap in 1936. He argued that purposeful action routinely produces consequences nobody intended, and that the most common causes are plain ignorance and error. Nothing has to go wrong for it to happen: the decision works, and the business around it responds in ways the plan never covered.
Leaders feel the pull hardest because the first result is the one they report on. A board asks whether the deal landed. Nobody asks what the team stopped doing while it was being chased.
The practical move is one extra question before you commit: if this works exactly as planned, what does it take from somewhere else, and who will notice first? Answer it with names and dates. A chain you can only describe in general terms hasn't been traced yet.
Once you know where the cost will land, worst-case scenario planning is how you protect against it while the decision plays out.
Our best order in years was weeks from landing when the accountant told Dan, our Managing Director, and me that we couldn't cover payroll. The deal was going exactly as planned, and that was the problem: most of our selling time had gone into it, so the smaller orders that time normally brought in had quietly stopped coming. Nobody had asked what chasing the deal would take from the rest of the pipeline, because the deal itself never looked like a risk. The purchase order arrived before month end and closed the gap, which meant the lesson nearly went unlearned.