It proceeds from the counter-assertion that Hamlet does, in fact, act forcefully long before the play's final act.
By Act V, Hamlet has invented the "mousetrap" of the play-within-a-play, slain Polonius and dragged his corpse away, persuaded the off-stage pirates to release him from captivity, and cleverly arranged the demise of his erstwhile schoolmates, Rosencrantz and Guildenstern.
This is why in the opening scenes, Claudius goes to such lengths to calm and soothe the concerns of the court.
When Hamlet returns to the court from school in Wittenburg, Germany, it is impossible that he can escape what awaits him.
His untimely death was marked by intense mourning at the court, as well it should have been for a man of his position.
However, Gertrude's marriage to Claudius before a month of mourning had passed could be interpreted as a breach of protocol.The obvious but simple answer is that if he did not take his time, we would have 'Hamlet: The Short Story' instead of 'Hamlet: The Classic Play'.There are, however, valid reasons for Hamlet's slow behaviour.Our sense that Hamlet delays action is reinforced by his demeanor and, above all, by his own words.When we first see the Prince on stage, dressed in black and self-exiled to the periphery of the court, he assumes the role of a critical observer making disparaging asides about Claudius and his consort.Among them are his public role in the monarchy of Denmark, his education, and the environment of Elsinore.Hamlet is first and foremost the Prince of Denmark.Such a transgression as the apparently unprovoked murder of a royal minister would open all sorts of questions for Claudius that he may be able to answer.Even Hamlet's private life is of public concern, especially when it comes to his selection of a wife.Moreover, after being told about the appearance of Ur-Hamlet's apparition on the walks of Elsinore Castle, Hamlet says to Horatio that he will speak with his father's ghost "though hell itself should gape/And bid me to hold my peace" (I, ii. Indeed, Hamlet casts aside the fears of Horatio and Marcellus about what awaits him when the Ghost beckons, and orders them to unhand him so that he can speak face-to-face with this awesome, fear-provoking figure.These prior acts are not those of a passive or timid soul.