If necessary, the government will force real estate agents to lower land prices.

Literal

Necessary [conditional-なら] government [topic-は] real-estate-agents [to-に] land [possessive-の] price [object-を] dropping [manner-よう] will-force [probability-だろう].

強制するだろう — だろう expresses probability. 落とすよう...強制する uses ように for an indirect command. A complex political/economic sentence.