Fortinbras challenges Claudius openly, unlike Hamlet who merely stages a play to test Claudius' guilt and tries (and fails) to kill the King at prayer. At first, Hamlet drew inspiration from a Player King's passion. In his "How all occasions" soliloquy he draws inspiration to take revenge from a real person. Fortinbras' actions may be one reason that Hamlet decides to arrange for the murder of Rosencrantz and Guildenstern upon his return to Denmark. He tries to emulate Fortinbras' lack of concern for the fates of common people. He says to Horatio:

They are not near my conscience; their defeat

Does by their own insinuation grow:

'Tis dangerous when the baser nature comes

Between the pass and fell incensed points

Of mighty opposites (V.5).

Hamlet, however, never is able to fully emulate Fortinbras' attitude. He kills Claudius only after he has become the victim of the king's plot to poison him. Fortinbras invades and takes control over the entire kingdom, not just the lands lost by his father to Old Hamlet. Although Hamlet professes admiration for...

The 'man of action' wins the war, even if Hamlet wins the audience's sympathy. This fate is prefigured in Hamlet's soliloquy about Fortinbras: Hamlet can see that people with Fortinbras' attitude are more effective in politics, even if he cannot fully embrace this sentiment while trying to make his thoughts full of blood and revenge. Although he ends his speech vowing to be more like Fortinbras, his vow seems hollow, given his previous skepticism about the Norwegian. Hamlet's admiration is similar to the admiration one might feel today when seeing someone put a great deal of passion and effort into a questionable pursuit. For example, when someone works extremely hard to make a great deal of money to buy fancy houses and cars, you might admire the effort, dedication, and determination of the individual but still question his ethical and materialistic values and goals.
Works Cited

Shakespeare, William. Hamlet. The Shakespeare Homepage. May 14, 2009.

http://shakespeare.mit.edu/hamlet/index.html