Though Hamlet struggles to answer the ghost's call to avenge his father, once he has decided to kill Claudius, he doesn't hesitate to eliminate those against him.

Claudius sends a letter to the King of England through Rosencrantz and Gildenstern to eliminate the Hamlet. When Hamlet discovers the letter, he forges another one, calling on the King of England to kill instead the messengers, his boyhood colleagues. He could just have them jailed, but eliminating them would probably delay the news from reaching Cauldius, giving Hamlet enough time to crush his enemy. And he used the hands of the English king to eliminate his enemy's lackeys. The Hamlet who forged the letter has evolved from the one questioning whether the ghost was lying to him and he changed from a bystander in royal politics to a key player. The Hamlet at the beginning of the play has disappeared and a more decisive and perhaps ruthless one takes his place. We can only speculate on what he would have done if he has survived. He may have ruled Denmark ruthlessly.

But he dies because he lacks a politician's experience and doesn't anticipate Laertes plotting with Claudius. He should have understood Laertes's feeling because he was also trying to avenge his father. But perhaps he believed Laertes was too upright to poison him. Yes, he, unlike Claudius who sets up a second offense with the poison wine, lacks a politician's experience and instinct. And we wonder how Hamlet would have maneuvered Denmark against Fortinbras, and for that matter, England.
Though Hamlet struggles to answer the ghost's call to avenge his father, once he has decided to kill Claudius, he doesn't hesitate to eliminate those against him. Claudius sends a letter to the King of England through Rosencrantz and Gildenstern to eliminate the Hamlet. When Hamlet discovers the letter, he forges another one, calling on the King of England to kill instead the messengers, his boyhood colleagues. He could just have them jailed, but eliminating them would probably delay the news from reaching Cauldius, giving Hamlet enough time to crush his enemy. And he used the hands of the English king to eliminate his enemy's lackeys. The Hamlet who forged the letter has evolved from the one questioning whether the ghost was lying to him and he changed from a bystander in royal politics to a key player. The Hamlet at the beginning of the play has disappeared and a more decisive and perhaps ruthless one takes his place. We can only speculate on what he would have done if he has survived. He may have ruled Denmark ruthlessly. But he dies because he lacks a politician's experience and doesn't anticipate Laertes plotting with Claudius. He should have understood Laertes's feeling because he was also trying to avenge his father. But perhaps he believed Laertes was too upright to poison him. Yes, he, unlike Claudius who sets up a second offense with the poison wine, lacks a politician's experience and instinct. And we wonder how Hamlet would have maneuvered Denmark against Fortinbras, and for that matter, England.