I told my wife "I swear by God that for every lie you say I divorce you whenever I remember this oath." I did not have a specific intention when I said this and I do not know whether I only wanted to deter her from lying or to actually divorce her if she does. My oath was a hasty reaction to her refusal to swear to never lie to me again. What is the ruling for this?
The opinion chosen for this fatwa, and the ruling derived from the opinions of some scholars, is that conditional divorce is effective if the conditions occur, and on the condition of the existence of the intention for divorce.
Based on this and in reference to the question, since the enquirer is unsure of his intention when he made this divorce contingent upon his oath, then his doubt renders the divorce ineffective. This is because the principle here is that certainty is not removed by doubt—certainty being the continuation of marital life that existed prior to making the oath for a conditional divorce, and doubt is the uncertainty of whether the marriage has been dissolved due to his wife lying. Based on this, if your wife lies, your oath does not effect a divorce.
And God Almighty knows best.