On May 5, the Indonesian rupiah closed at 17,445 against the US dollar — its weakest level on record. By evening, Bank Indonesia had tightened foreign-exchange rules for the third time in two months, capping cash dollar purchases without underlying documentation at US$25,000, down from $100,000 in March. Governor Perry Warjiyo, briefing reporters alongside President Prabowo Subianto's economic ministers, declared the currency undervalued and the central bank's resolve undimmed.
The rupiah may yet recover or weaken further, but the question of Bank Indonesia's policy toolkit stands either way. The instruments are now being deployed faster than at any point since the 1997-98 Asian financial crisis. Whether they still fit the problem they were built for is the harder question — and one Jakarta's central bank peers in Manila, Mumbai, Seoul, and elsewhere in Asia are beginning to ask themselves.
Reserves Dwindle as Pressure Mounts
In the first quarter of 2026, Bank Indonesia drew down $8.3 billion from its foreign exchange reserves, leaving the stockpile at $148.2 billion by end-March, the lowest since July 2024. The pattern extends across the region: the Indian rupee, the Philippine peso, and the South Korean won have each hit record or multi-year lows, with the won recently touching its lowest level in 17 years. On paper, these currencies should have some breathing room. The US Dollar Index is down 10.91% over the past 12 months, the US Federal Reserve is expected to cut rates further, and the dollar's share of global reserves has slipped from 66% in 2015 to 56% by 2025. Clearly, something in the usual transmission between a softer dollar and calmer emerging markets has stopped working.
A recent analysis noted that the ongoing Iran war has disrupted the familiar dynamic in which geopolitical tension meant buying dollars and selling Asia, with Southeast Asian currencies now diverging according to their own fundamentals. Indonesia fills in the less comfortable half of that picture. The global reserve-currency transition under way — echoing the pound sterling's fall from 70% of global reserves in 1940 to 2% by 1980 — is a slow structural process. Harvard's Kenneth Rogoff, among others, argues that dollar dominance has probably reached its peak.
The more immediate question is whether the policy playbook that emerging markets assembled in the aftermath of the 1997-98 Asian financial crisis still offers sufficient protection during the de-dollarization transition. Much of the public debate revolves around questions easy to pose but difficult to answer — whether the yuan, gold, or some combination will eventually take the dollar's place. A more tractable story unfolds inside the operations rooms of emerging-market central banks, where the tools built to manage life under dollar dominance are increasingly mismatched with the dollar they now face.
Four Instruments, One Currency
For almost three decades, the working consensus among emerging-market policymakers has been fairly stable: build reserves, anchor inflation credibly, intervene with discretion, keep policy rates roughly aligned with external conditions. That framework was built for a world of steady dollar dominance and predictable Fed cycles. Those assumptions and conditions, however, no longer hold. The dollar now moves on Trump-era policy whiplash, on disputes about Federal Reserve independence, and on geopolitical shocks whose rhythm does not fit standard intervention models.
Bank Indonesia is currently deploying four instruments at once — offshore non-deliverable forwards (NDFs), domestic non-deliverable forwards (DNDFs), the spot market, and secondary government bonds — in the posture of an institution assembling a rupiah defense from every available tool, because no single instrument carries enough weight on its own. Tuesday's tightening of dollar-purchase thresholds adds an administrative fifth. Bank Indonesia's willingness to layer on capital-flow management tools, spelled capital controls, alongside market intervention is itself a significant signal: the conventional toolkit is no longer enough.
The structural backdrop, however, makes these tools harder to wield. Indonesia exports commodities priced in dollars — nickel, coal, palm oil — while importing dollar-denominated essentials such as refined fuel, capital goods, and food. When oil prices spiked because of the Iran war, rising import costs outpaced commodity export gains, widening rather than narrowing the trade deficit. A multipolar currency order offers ways out of this asymmetry in principle, but the plumbing is still being laid. ASEAN's Local Currency Transaction framework covers only a thin slice of regional trade, and BRICS payment infrastructure is still more a geopolitical signaling device than a functioning financial clearing system.
As European Central Bank chief economist Philip Lane has warned, heavy reliance on dominant payment systems leaves countries “outsourcing” their own financial infrastructure. Emerging markets are thus being asked to manage yesterday's crisis with tomorrow's tools — tools that have yet to be built and deployed.
Monetary Policy Autonomy Under Siege
The third element of the old playbook, monetary policy autonomy, has quietly become the most constrained. The standard prescription — cut rates to support growth, raise them to defend the currency — assumes domestic and external objectives can be balanced. But that balance has narrowed. Bank Indonesia has cut rates by 150 basis points since September 2024 to 4.75%. That's defensible on domestic grounds with inflation inside the 2.5% target band, and GDP projected at between 4.9% and 5.7%. Each cut, though, narrows the rate differential with the US Fed and weighs on capital flows, leaving the central bank caught between the growth its government expects and the currency stability its external balance demands.
The pressure extends beyond Indonesia. The Reserve Bank of India has intervened heavily even as its reserves face similar strain. The Japanese yen has also been under pressure, nearing 160 to the dollar, with traders eyeing historic levels. Meanwhile, Trump's Iran conflict undermines dollar dominance across Asia, adding to the uncertainty. The old playbook, built for a different era, is no longer sufficient. Emerging markets must now navigate a world where the dollar's role is shifting, and the tools to manage that shift are still under construction.
