Is God still God? Is God still the Lord of history? The difference is this: When God used a catastrophe as an arm of judgment in the Old Testament, we know that his judgment was behind the catastrophic event because we have the benefit of the written revelation telling us that this was God's hand in history. As we live out our lives and see nations suffer catastrophes and calamity strike people, we don't know exactly what the relationship is between those catastrophes and the judgment of God.
Let me construct a biblical parallel here. In the ninth chapter of John's Gospel, the Pharisees raised this question about a man born blind: Was this man born blind because he was a sinner or because his parents were sinners? Jesus' answer: It was neither one of them. He was born blind for another reason altogether. It wasn't done as a matter of course, as an expression of divine judgment. That text and the whole book of Job should restrain us in the case of individuals from ever assuming that a person's tragedy or catastrophe or calamity is a direct act of divine judgment. Now, it may be. We see countless cases in Holy Scripture where God does, in fact, bring calamity upon the house of a person who has been flagrant in disobedience toward God. The Bible is saying that if we are guilty, God may withhold judgment until later, or we may receive temporal judgment in this world right now at his hands. We never know for sure whether the calamity we experience as individuals is a direct act of judgment or not. What is true of individuals is also true of nations.
I remember hearing Billy Graham say in a sermon a few years ago, "If God does not bring judgment upon the United States of America, he's going to have to apologize to Sodom and Gomorrah." Remember, Jesus warned the cities that heard his message, Chorazin and Bethsaida, that the Day of Judgment would be more tolerable for Sodom and Gomorrah than it would be for them. While we no longer have prophetic interpretation of God's reasoning for bringing judgment, we do know that no nation is ever exempt from the judgment of God.