At what point does the conflict between Mr. White and the paw actually begin? Explain.

This is a fantastic question. Let me give you a play by play of sorts.  At first, Mr. White is intrigued by the paw.  He listens intently at the stories of Sergeant Major Morris.  When Morris speaks of the power and evil of the paw and throws it into the fire, Mr. White quickly saves it.  This action shows that Mr. White wants to protect the paw.  There is no conflict yet. 

After Mr. White...

This is a fantastic question. Let me give you a play by play of sorts.  At first, Mr. White is intrigued by the paw.  He listens intently at the stories of Sergeant Major Morris.  When Morris speaks of the power and evil of the paw and throws it into the fire, Mr. White quickly saves it.  This action shows that Mr. White wants to protect the paw.  There is no conflict yet. 

After Mr. White makes a wish, whether he believes in the paw or not, the conflict begins.  In fact, that night as he is looking into the fire, he sees face.  He sees a horrible face of monkey.  Here is the quote:

One face was so horrible and monkey-like he stared at it in amazement.

This starts the conflict.  Mr. White begins to fear.  The next morning, Mr. White believes that the paw also moved. This scares him. Shortly thereafter, Herbert died at work in an accident. This intensifies the conflict.  When Mr. White makes his second wish - to have his son back, he is uneasy.  The only reason he makes this wish is because of Mrs. White's insistence.   When there is a knock at the front door, fear grips him.  Finally, he wishes everything away. This last action shows that he completely believes in the power of the paw and accepts defeat.  In other words, he will cut his loses and move on. The paw wins.