Like the German mark, French franc and Finnish markka, Sweden’s krona may one day become a relic of the past — if the country’s proponents of the euro get their way.While Sweden is a longstanding member of the European Union, it’s thus far resisted joining the almost three-decade-old common currency. But tighter integration with the EU is starting to look more attractive as a shield against heightened geopolitical instability and the cooling of transatlantic relations under US President Donald Trump.Public support for euro adoption has grown in recent years in the Nordics’ largest economy, although it’s still a divisive issue and a currency switch would likely take years to complete. Nonetheless, a shift in Sweden’s position would be a milestone for the EU and add credibility to the euro — at a time when Trump’s unpredictability is undermining confidence in the dollar. Why isn’t Sweden part of the eurozone?Sweden joined the EU in 1995 and is legally committed to euro adoption once certain economic criteria are met.But after the single currency was launched by the bloc in 1999, Sweden chose not to join for political and economic reasons, including concerns about sovereignty and losing the krona’s role in buffering the economy. In a non-binding Swedish referendum in 2003, some 56% of voters rejected adopting the euro and successive governments have respected that result.Economically, Sweden has preferred to retain control over its monetary policy and maintain a floating exchange rate. It’s stayed outside the EU’s ERM II mechanism that manages the euro’s exchange rate with other currencies in the bloc. Participation in ERM II is one of the requirements for adopting the euro.Sweden is one of just six EU countries in the 27-member bloc that still use their own currencies — the others being the Czech Republic, Denmark, Hungary, Poland and Romania. Denmark has negotiated a formal opt-out from euro adoption. Why is Sweden rethinking euro adoption now?Government ministers have argued that the geopolitical and economic landscape has changed significantly since Sweden last seriously considered joining the single currency, bolstering the case for closer integration with the rest of the EU.The tectonic shifts in recent years include Russia’s invasion of Ukraine — which prompted Sweden to pivot from a long history of military non-alignment and join the North Atlantic Treaty Organization — and China’s growing global influence. But above all, the deterioration of transatlantic relations under Trump is raising doubts about the long-term viability of a free-floating krona.These concerns center on the vulnerability of being outside a larger currency bloc during a geopolitical crisis, when the small krona could be left exposed to potentially intense market volatility.The economic debate around euro adoption has also evolved. This was reflected in a December analysis that was published by the Swedish Free Enterprise Foundation and led by influential economist Lars Calmfors, who helmed the government panel to evaluate a currency switch ahead of the 2003 referendum. While the panel’s recommendation back then was to wait, Calmfors’ new evaluation pointed to greater commercial benefits for euro-area members than previously assumed and diminished advantages from retaining independent monetary policy. What would be the advantages for Sweden of joining the euro?Calmfors and other observers say that sharing a currency with the 21 euro-area countries would make trade easier and more predictable, benefiting Sweden’s broader economy. More than 60% of the Nordic country’s goods trade is with the rest of the EU. Eliminating exchange-rate fluctuations — which can at times be sharp — would reduce costs and uncertainty for importers and exporters.Adopting the euro would also allow Sweden to bind itself more closely to its European neighbors, at a time when leaders are calling for a stronger and more coordinated response to Trump’s reshaping of the world order and the return of great-power politics. What are the risks for Sweden if it drops the krona?Losing the krona would mean giving up independent monetary policy, which currently allows Sweden to set interest rates according to domestic conditions rather than following the decisions of the European Central Bank for the wider euro area.The floating exchange rate has also been viewed as an “airbag” for Sweden’s export-dependent economy. That means that the krona typically weakens in times of crisis, cushioning the impact on economic growth by making Swedish goods cheaper abroad.There are concerns about exposure to euro area debt, which sits at more than 80% of GDP, according to Eurostat. Sweden’s debt-to-GDP ratio is only around 33%. Oscar Sjostedt, a lawmaker from the nationalist Sweden Democrats party, has said that current borrowing trends in the euro area could lead to the common currency’s collapse. What’s standing in the way of a currency switch?A key obstacle is public opinion. While Swedes have gradually warmed to the euro, more people are still against adopting the currency than for it. Many observers say a second referendum would be needed to lend legitimacy to any decision to switch currency.Political views are also divided. Prime Minister Ulf Kristersson’s center-right Moderate Party, which leads the minority three-party coalition government, is formally in favor of joining the euro. But it has been cautious about actively pushing the issue and is polling in a vulnerable third place among voters.On the opposition bench, the poll-leading Social Democrats have yet to take an official position on euro adoption. The Sweden Democrats — the second-most popular party among voters — are strongly against a currency switch.There’s unlikely to be significant movement on the issue until after September’s general election. Finance Minister Elisabeth Svantesson said in January that she would launch an inquiry into the pros and cons of euro adoption if the current government remains in power. How complicated would it be for Sweden to switch currency?The transition would likely be relatively straightforward. Sweden meets most of the EU’s economic criteria for euro adoption, including sound public finances and historically low inflation.It would need to participate in the ERM II exchange-rate mechanism and keep the krona stable against the euro for at least two years. Economist Calmfors estimates that the full process of euro adoption would take at least four years.In practical terms, switching to euro use in Sweden would effectively be a coding issue. The economy is almost completely cashless, which would avoid the cost and complexity of scrapping krona notes and coins.