Why do Japanese nominalize in sentences? "no wa" and "no ga"

[Shokai]

For those of you who might not know, a nominative is basically making a non-noun into a noun.

For example in the sentence:

gaikoku wo manabu no wa, muzukashii desu ne. (Foreign languages are difficult to learn, arent they?)

Why cant you just say:

gaikoku wo manabu wa muzukashii desu ne.

Studying from my grammar book, no wa, no ga play a role in nominalization. What exactly are no wa and no ga?

PS: if you type in Japanese, please type in Romaji. Im having a difficult time installing Japanese font.

Thanks  

[Shokai]

Errrr, please delete this thread. I accidentally might have clicked the submit button twice (slow computer).

Sorry sweatdrop