The people living in Jerusalem were living under the threat of an Assyrian's attack. They needed to learn to trust God rather than rely on other nations to repel the attack. Yet God's response was not to become a bigger bully than the Assyrians but to promise a child, Jesus.
Furthermore it wasn't a temporary solution but one with implications for the future of Israel and the whole world. We look for quick solutions to immediate problems but God looks beyond symptoms to solutions which will change people's hearts and teach them to trust him.
Moreover God is so powerful he only has to send a child—a child will solve the world's problems not the strength and power of a military leader. This is one of the many paradoxes of the Christian life. We gain through means which are the opposite to what we expect.
Many historical leaders became dictators by trying to be god-like, ruling with power and ruthlessness. Yet to truly become God-like means to be humble. Jesus "is gentle and humble in heart" (Matthew 11:29). He "did not come to be served, but to serve, and to give his life as a ransom for many" (Mark 10:45) and Jesus is the "exact representation" of God's being (Hebrews 1:3).
This has repercussions for us today. We don't have to strive to win through our cleverness, our strength or power, rather we trust in God and in his ability to find solutions in the unexpected power of humility.
A humble attitude towards God and others opens the way for surprising solutions.