Thinkpads come in different flavours, and the have very different quality. Either get a T-series, or X-series (X series is basically smaller version of T). Or if it's a used one, the later A-series are good as well (A series means AMD instead of Intel). The old A - series were crap. Nowadays T and X series have AMD also (if model ends with 5, it's AMD).
T and X series have MIL certification.
For example there's also X1 Extreme (costs around 3000€), but quality wise it's a lot worse than T or X series, because it does not have the MIL certificate.