SPIEGEL ONLINE: One year after the financial crisis,  the people who triggered it on Wall Street are doing great.  First the taxpayers bailed them out and now they are swimming in bonuses again.

Jakob von Weizsäcker: It is scandalous how the financial sector pocketed billions in profits in the good years and then in the crisis passed on billions in losses to taxpayers. The system is sick and needs to be reformed. But I am not certain whether salary limits for bankers should be the central issue of the G-20 summit, as German Chancellor Angela Merkel and French President Nicolas Sarkozy have proposed. It is tempting, because this is the issue voters understand the most, but it is not so important.

SPIEGEL ONLINE: What's more important?

Weizsäcker: Capital requirements for banks around the world. If institutions built up bigger buffers, then shareholders would be held liable a lot faster if something went wrong. That would automatically lead them to pay their managers bonuses for exercising caution rather than taking big risks. The G-20 states also need to ensure that the monitoring of large international banks takes place on the international or at least pan-European level. Otherwise the same thing will happen again during the next crisis as happened during this one: Banks behave internationally when it comes to profits, but when it comes to losses, national taxpayers get stuck footing the bill.

SPIEGEL ONLINE: But will there be an agreement in Pittsburgh?

Weizsäcker: Many technical questions have already been negotiated prior to the summit. The early signs are positive that there will be an agreement on these issues. But what's perhaps more important is the message that Pittsburgh is sending, namely that people have understood the importance of these questions and that they don't just want to return to business as usual after the crisis.

SPIEGEL ONLINE: Officials in Pittsburgh won't even be negotiating the "exit strategy," the issue of when central banks and countries should allow their billions-strong economic aid packages to end.

Weizsäcker: No, but this discussion is happening despite that. It's not actually that complicated. In 2010, governments are expected to continue with their economic stimulus packages and banks that still need it will be provided with fresh capital. It will be expensive again, but it is necessary. Then, one year later, the governments must start to reduce their budget deficits -- not abruptly in such a way that it would jeopardize the economy, but nevertheless efficiently. Politically, that will be an enormous challenge -- for Germany, too. After all, such policies will require massive spending cuts and probably increases in taxes, too. But if the cost-cutting strategy succeeds, then there will be few worries about inflation and the central banks will be able to keep key interest rates low for some time to come, thus bolstering the economy.

SPIEGEL ONLINE: And if it doesn't?

Weizsäcker: Then things will get ugly. And there will be conflicts between central banks and governments over what should happen first: an end to the policies of low-interest rates or a reduction of national deficits totalling in the billions.

SPIEGEL ONLINE: The Americans and the British want to strengthen the global economy by forcing "surplus" countries like China and Germany, which export more than they import, to increase domestic consumption. Should Germany be concerned about its position as export world champion?

Weizsäcker: We shouldn't allow the buck to be passed to us. The causes of our trade surplus are not at all comparable with those in China. After all, there it is prescribed by the state. But that also shouldn't prevent us from rethinking the German economic model, which is heavily reliant on exports. An export-oriented strategy is really a double-edged sword. On the one hand, global trade is such a good thing precisely because it allows countries to specialize. Consider the German automobile industry -- a great success story. At the same time, such success often makes a country dependent on the ups and downs of a particular industry. When things aren't going so well, the export sectors need to be subsidized by the rest of the economy.