cause of action on an estoppel law

[МашаTs]

пожалуйста, помогите разобраться! не понимаю суть estoppel и принцип "shield and not a sword"
Выдержка, на которую опирается сторона, выдвинувшая встречный иск:
"... while a party cannot in terms found a cause of action on an estoppel he may, as a result of being able to relay on an estoppel, succeed in a case of action, one on which without being able to rely on that estoppel he would necessarily have failed."

There is one further issue raised on behalf of AAA in answer to BBB's estoppel plea, namely that estoppel cannot be invoked so as to give rise to a cause of action: as the principle is often stated, it is a shield and not a sword.

[Alex16]

На той неделе Оксана С. отвечала по поводу эстоппеля...

[МашаTs]

Спасибо!
буду искать

[nephew]

http://www.multitran.ru/c/m.exe?a=4&MessNum=83455&l1=1&l2=2&SearchString=эстоппель&MessageNumber=83455

[MashaTs]

nephew,
спасибо!
только что прочитала.