1)
How long did the war continue?
1.
Malbim: It was the last five years that Ish Boshes ruled.
2)
Why was Beis Sha'ul diminishing?
1.
Malbim: Many of Yisrael abandoned Ish Boshes and went after David, like it says in Divrei ha'Yamim I, 12. This is why it is written that Ish Boshes was king only for two years.
