"'For the revelation awaits an appointed time; it speaks of the end and will not prove false. Though it linger, wait for it; it will certainly come and will not delay.'" NIV translation
God is telling the prophet that He is going to handle the Babylonians but reminds Habakkuk that it will be in His perfect timing. God has an "appointed time" for everything in our lives and in the lives of everything. We, as people, get restless and want things to happen when we think that they should and this can lead to many false prophets telling us what we want to hear. We, like the people of Judah, must trust in God's ability to handle things at just the right time. That is what the apostle Peter was reminding us about in his second letter.
"'See, he is puffed up; his desires are not upright - but the righteous will live by his faith -'" NIV translation
Pride was the very thing that caused Satan to fall from heaven and it is the same thing that was at work in the Babylonians.
This same sin is at work in much of the world today as everywhere you look a man is measured by what he has or what he does.
God looks after the humble (which is the opposite of pride) as they trust in Him and not their own efforts.
"'indeed, wine betrays him; he is arrogant and never at rest. Because he is as greedy as the grave and like death is never satisfied, he gathers to himself all the nations and takes captive all the peoples.'" NIV translation
Pride opens the door to other sin as we see here. Because of that pride, the Babylonians lived it up with wine and constantly wanted more and more territory. The same is true today as many think so highly of themselves that they don't believe that they will ever have to answer to anyone else for their actions. We see our fellow man grabbing for more and more of the things of this world as the system rewards those who do so but judgment is coming as we see in Revelation 18.