The twin shocks of the Israeli-US attack on Iran and Donald Trump’s tariff war come as global GDP growth continues to slow precipitously. Given that it doesn’t take much to tip an economy nearing its “stall speed” into outright recession, these crises and their combined effects are setting the stage for a worldwide downturn.
以色列與美國對伊朗的雙重打擊，以及唐納德·川普的關稅戰，正值全球 GDP 成長持續急劇放緩之際。鑑於經濟接近「失速點」時，稍有風吹草動便可能陷入明顯衰退，這些危機及其綜合影響正為全球經濟衰退鋪路。
NEW HAVEN – The outbreak of a new war in the Middle East, together with a destructive tariff war, makes for a lethal combination in a sluggish world economy. Notwithstanding the possibility of a tentative ceasefire, the odds of imminent global recession have increased sharply. 新港 – 中東爆發新一輪戰爭，加上破壞性的關稅戰，對疲弱的全球經濟構成致命組合。儘管存在暫時停火的可能性，全球經濟即將陷入衰退的機率已大幅上升。
One shock was bad enough. US President Donald Trump’s tariffs, wherever they eventually settle, imply downside risks to global growth. But the potential for a second shock – a war between Israel and Iran that has now ensnared the United States – compounds the problems for an increasingly vulnerable world economy. It fits with my theory of cyclical risk: it doesn’t take much to tip an economy nearing “stall speed” into outright recession. 一次衝擊已經夠糟了。美國總統唐納·川普的關稅政策，不論最終落在哪個水平，都意味著全球經濟成長面臨下行風險。但第二次衝擊的可能性——以色列與伊朗之間的戰爭，現已將美國捲入其中——使得本已日益脆弱的世界經濟問題更加複雜。這與我對週期性風險的理論相符：當經濟接近「停擺速度」時，稍有風吹草動就可能將其推入全面衰退。
This simple rule has worked remarkably well in predicting global recessions over the past 45 years. Unlike a recession in an individual economy, which generally reflects a contraction of real output, one at the global level typically involves about half the world’s economies contracting while the remainder continue to expand. As a result, a worldwide recession is usually associated with global GDP growth slowing to the still positive 2-2.5% range – a shortfall of 0.8 to 1.3 percentage points from the post-1980 trend of 3.3%. The exceptions were in 2009 and 2020, when the global financial crisis and the pandemic, respectively, caused outright contractions in global output. 這個簡單的規則在過去 45 年中對預測全球經濟衰退表現得非常準確。與單一經濟體的衰退通常反映實質產出收縮不同，全球層級的衰退通常涉及約一半的世界經濟體收縮，而其餘經濟體則持續擴張。因此，全球經濟衰退通常伴隨全球 GDP 成長放緩至仍為正值的 2-2.5%區間——比 1980 年後 3.3%的趨勢成長低 0.8 到 1.3 個百分點。例外情況是 2009 年和 2020 年，分別因全球金融危機和疫情導致全球產出出現明顯收縮。
The stall speed holds the key to cyclical risk assessment. It can be thought of as a zone of vulnerability, measured by significant downside deviations from trend growth. Looking back over the past 45 years, I would place the global economy’s stall speed in the 2.5-3% range: when in this zone, the world lacks the resilience needed to withstand a shock. That is what happened in each of the past four global recessions. 停滯速度是週期性風險評估的關鍵。它可被視為一個脆弱區域，以相較於趨勢成長的顯著下行偏差來衡量。回顧過去 45 年，我會將全球經濟的停滯速度定在 2.5-3%區間：當處於此區間時，全球缺乏抵禦衝擊所需的韌性。這正是過去四次全球經濟衰退中所發生的情況。
Fast-forward to today. According to the International Monetary Fund’s latest World Economic Outlook, global GDP growth is expected to slow to 2.8% in 2025 – right in the middle of the stall-speed zone. Whereas recent global recessions were the result of single shocks, today the world economy could be hit by two: a tariff war and a kinetic war in the Middle East. The possibility of a double-shock combination only increases the odds of global recession; in forecasting circles, it’s as close to a smoking gun as you can get. 快轉到今天。根據國際貨幣基金組織最新的《世界經濟展望》，全球 GDP 增長預計在 2025 年放緩至 2.8％——正處於停滯速度區間的中間。過去的全球經濟衰退多因單一衝擊所致，而如今世界經濟可能同時遭受兩大衝擊：關稅戰爭與中東的動能戰爭。雙重衝擊的可能性只會增加全球經濟衰退的機率；在預測界，這幾乎是最明顯的證據。
As always, the devil is in the details – in this case, the specific transmission effects of the two shocks to global growth. The trade war, by now, is old news. My assumption is that the Trump tariff package that eventually emerges from ongoing legal disputes will feature something close to a 10% global tariff, a considerably higher tariff rate for China, and steeper product-specific tariffs aimed at protecting America’s legacy industries, such as motor vehicles and parts, steel, and aluminum. 一如既往，關鍵在於細節——在此情況下，是兩大衝擊對全球增長的具體傳導效應。貿易戰到現在已是老生常談。我的假設是，最終從持續的法律爭議中產生的川普關稅方案，將包含接近 10％的全球關稅，對中國的關稅率則更高，並針對美國傳統產業如汽車及零件、鋼鐵和鋁材等實施更嚴格的產品特定關稅。
PS Events: London Climate Action Week 2025 PS 活動：2025 年倫敦氣候行動週
Did you miss our London Climate Action Week event? 錯過了我們在倫敦氣候行動週的活動嗎？
Click here to watch the whole broadcast, featuring panel discussions on the role of business in filling the global climate-leadership gap. 點擊此處觀看完整直播，內容包括關於企業在填補全球氣候領導力缺口中角色的專題討論。
Watch Now 立即觀看
The 10% global tariff represents a roughly five-fold increase from the 1.9% average effective tariff rate during the 30 years before Trump’s “Liberation Day” back in early April – a shock by any standards. That creates downside risks for the still export-dependent Chinese economy and major uncertainty for the US economy, almost surely leading to pullbacks in capital spending and hiring, both of which are dependent on businesses’ stable expectations of the future. With the US and Chinese economies collectively accounting for a little more than 40% of cumulative global GDP growth since 2010, one should not underestimate a tariff war’s potential damage to the world economy. 全球 10%的關稅率，較川普於四月初所謂的「解放日」前 30 年平均有效關稅率 1.9%約增加了五倍，無論如何看都是一大衝擊。這對仍依賴出口的中國經濟構成下行風險，對美國經濟則帶來重大不確定性，幾乎肯定會導致資本支出和招聘的縮減，而這兩者都依賴企業對未來的穩定預期。由於美中經濟合計自 2010 年以來約占全球累計 GDP 增長的 40%以上，不應低估關稅戰對世界經濟可能造成的損害。
As for the Middle East, the macroeconomic impact of wars is typically measured through oil prices. Following Israel’s launch of strikes against Iran on June 13, oil prices initially soared, but from three-year lows, and remained well below post-2022 averages. Then, in the immediate aftermath of Trump’s June 23 ceasefire announcement, oil prices retraced much of the war-related run-up. If hostilities continue – always a possibility in the Middle East – there will be significant upside risks to energy and other commodity prices as markets start to worry about Iran’s options for retaliation, which could include disruption of oil production and distribution, as well as of shipping lanes. On balance, the US bombing of Iranian nuclear enrichment facilities on June 21 has injected a new element of uncertainty into an already hyper-volatile world. 至於中東，戰爭的宏觀經濟影響通常透過油價來衡量。以色列於 6 月 13 日對伊朗發動攻擊後，油價最初飆升，但是從三年低點起漲，且仍遠低於 2022 年後的平均水平。隨後，在川普於 6 月 23 日宣布停火後，油價回吐了大部分因戰爭而上漲的幅度。如果敵對行動持續——這在中東始終是可能的——能源及其他大宗商品價格將面臨顯著的上行風險，因市場開始擔憂伊朗的報復選項，可能包括擾亂石油生產與分銷，以及航運通道。綜合來看，美國於 6 月 21 日轟炸伊朗核濃縮設施，為本已極度波動的世界局勢注入了新的不確定因素。
It is far too early to foretell how US entry into Israel’s war against Iran will affect global energy prices. But in one sense, the situation is reminiscent of Saddam Hussein’s invasion of Kuwait in August 1990, which led to a doubling of oil prices within three months. Significantly, the world economy was already slowing toward a 2.5% stall speed in 1991, and the war-related energy shock led to a mild global recession in 1992-93. 現在判斷美國介入以色列對伊朗戰爭將如何影響全球能源價格還為時過早。但在某種意義上，這情況讓人聯想到 1990 年 8 月薩達姆·侯賽因入侵科威特，當時油價在三個月內翻倍。值得注意的是，當時全球經濟已在 1991 年放緩至約 2.5%的停滯速度，而戰爭引發的能源衝擊導致 1992 至 1993 年出現輕微的全球經濟衰退。
The key to the near-term outlook is not US tariffs or the Iran war, but their geopolitical interplay. These shocks have the potential to feed on each other, threatening a vulnerable world economy that is already at risk of stalling out. Cyclical calls are never a sure thing. But this year’s twin shocks make a global recession look increasingly likely.
It takes only one side to start a war, but it takes all parties involved to end one. In this latest crisis in the Middle East, initiative has passed from Israel to the US and now to Iran, which now must decide if the US attack is the beginning of the end or the end of the beginning.
thinks the US attacks on three nuclear sites raise more questions than have been answered so far.
Military strikes might slow down a nuclear program, but they cannot impose long-term restraint – especially when they are carried out by powers that flout the very rules they claim to be enforcing. The US and Israel are likely to learn this the hard way, as Iran abandons all doubts about pursuing nuclear breakout.
struggles to see how any country would put its faith in the global nonproliferation regime at this point.
While Israel and the United States have sound reasons for seeking to destroy Iran’s nuclear facilities, military force alone will not bring about a lasting resolution. That can come only through diplomacy – and there has never been a better time for the US to extract concessions.
argues that there is no military solution to the Islamic Republic's pursuit of the bomb.
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NEW HAVEN – The outbreak of a new war in the Middle East, together with a destructive tariff war, makes for a lethal combination in a sluggish world economy. Notwithstanding the possibility of a tentative ceasefire, the odds of imminent global recession have increased sharply.
新港 – 中東爆發新一輪戰爭，加上破壞性的關稅戰，對疲弱的全球經濟構成致命組合。儘管存在暫時停火的可能性，全球經濟即將陷入衰退的機率已大幅上升。
One shock was bad enough. US President Donald Trump’s tariffs, wherever they eventually settle, imply downside risks to global growth. But the potential for a second shock – a war between Israel and Iran that has now ensnared the United States – compounds the problems for an increasingly vulnerable world economy. It fits with my theory of cyclical risk: it doesn’t take much to tip an economy nearing “stall speed” into outright recession.
一次衝擊已經夠糟了。美國總統唐納·川普的關稅政策，不論最終落在哪個水平，都意味著全球經濟成長面臨下行風險。但第二次衝擊的可能性——以色列與伊朗之間的戰爭，現已將美國捲入其中——使得本已日益脆弱的世界經濟問題更加複雜。這與我對週期性風險的理論相符：當經濟接近「停擺速度」時，稍有風吹草動就可能將其推入全面衰退。
This simple rule has worked remarkably well in predicting global recessions over the past 45 years. Unlike a recession in an individual economy, which generally reflects a contraction of real output, one at the global level typically involves about half the world’s economies contracting while the remainder continue to expand. As a result, a worldwide recession is usually associated with global GDP growth slowing to the still positive 2-2.5% range – a shortfall of 0.8 to 1.3 percentage points from the post-1980 trend of 3.3%. The exceptions were in 2009 and 2020, when the global financial crisis and the pandemic, respectively, caused outright contractions in global output.
這個簡單的規則在過去 45 年中對預測全球經濟衰退表現得非常準確。與單一經濟體的衰退通常反映實質產出收縮不同，全球層級的衰退通常涉及約一半的世界經濟體收縮，而其餘經濟體則持續擴張。因此，全球經濟衰退通常伴隨全球 GDP 成長放緩至仍為正值的 2-2.5%區間——比 1980 年後 3.3%的趨勢成長低 0.8 到 1.3 個百分點。例外情況是 2009 年和 2020 年，分別因全球金融危機和疫情導致全球產出出現明顯收縮。
The stall speed holds the key to cyclical risk assessment. It can be thought of as a zone of vulnerability, measured by significant downside deviations from trend growth. Looking back over the past 45 years, I would place the global economy’s stall speed in the 2.5-3% range: when in this zone, the world lacks the resilience needed to withstand a shock. That is what happened in each of the past four global recessions.
停滯速度是週期性風險評估的關鍵。它可被視為一個脆弱區域，以相較於趨勢成長的顯著下行偏差來衡量。回顧過去 45 年，我會將全球經濟的停滯速度定在 2.5-3%區間：當處於此區間時，全球缺乏抵禦衝擊所需的韌性。這正是過去四次全球經濟衰退中所發生的情況。
Fast-forward to today. According to the International Monetary Fund’s latest World Economic Outlook, global GDP growth is expected to slow to 2.8% in 2025 – right in the middle of the stall-speed zone. Whereas recent global recessions were the result of single shocks, today the world economy could be hit by two: a tariff war and a kinetic war in the Middle East. The possibility of a double-shock combination only increases the odds of global recession; in forecasting circles, it’s as close to a smoking gun as you can get.
快轉到今天。根據國際貨幣基金組織最新的《世界經濟展望》，全球 GDP 增長預計在 2025 年放緩至 2.8％——正處於停滯速度區間的中間。過去的全球經濟衰退多因單一衝擊所致，而如今世界經濟可能同時遭受兩大衝擊：關稅戰爭與中東的動能戰爭。雙重衝擊的可能性只會增加全球經濟衰退的機率；在預測界，這幾乎是最明顯的證據。
As always, the devil is in the details – in this case, the specific transmission effects of the two shocks to global growth. The trade war, by now, is old news. My assumption is that the Trump tariff package that eventually emerges from ongoing legal disputes will feature something close to a 10% global tariff, a considerably higher tariff rate for China, and steeper product-specific tariffs aimed at protecting America’s legacy industries, such as motor vehicles and parts, steel, and aluminum.
一如既往，關鍵在於細節——在此情況下，是兩大衝擊對全球增長的具體傳導效應。貿易戰到現在已是老生常談。我的假設是，最終從持續的法律爭議中產生的川普關稅方案，將包含接近 10％的全球關稅，對中國的關稅率則更高，並針對美國傳統產業如汽車及零件、鋼鐵和鋁材等實施更嚴格的產品特定關稅。
PS 活動：2025 年倫敦氣候行動週
PS Events: London Climate Action Week 2025
PS 活動：2025 年倫敦氣候行動週
Did you miss our London Climate Action Week event?
錯過了我們在倫敦氣候行動週的活動嗎？
Click here to watch the whole broadcast, featuring panel discussions on the role of business in filling the global climate-leadership gap.
點擊此處觀看完整直播，內容包括關於企業在填補全球氣候領導力缺口中角色的專題討論。
Watch Now 立即觀看
The 10% global tariff represents a roughly five-fold increase from the 1.9% average effective tariff rate during the 30 years before Trump’s “Liberation Day” back in early April – a shock by any standards. That creates downside risks for the still export-dependent Chinese economy and major uncertainty for the US economy, almost surely leading to pullbacks in capital spending and hiring, both of which are dependent on businesses’ stable expectations of the future. With the US and Chinese economies collectively accounting for a little more than 40% of cumulative global GDP growth since 2010, one should not underestimate a tariff war’s potential damage to the world economy.
全球 10%的關稅率，較川普於四月初所謂的「解放日」前 30 年平均有效關稅率 1.9%約增加了五倍，無論如何看都是一大衝擊。這對仍依賴出口的中國經濟構成下行風險，對美國經濟則帶來重大不確定性，幾乎肯定會導致資本支出和招聘的縮減，而這兩者都依賴企業對未來的穩定預期。由於美中經濟合計自 2010 年以來約占全球累計 GDP 增長的 40%以上，不應低估關稅戰對世界經濟可能造成的損害。
As for the Middle East, the macroeconomic impact of wars is typically measured through oil prices. Following Israel’s launch of strikes against Iran on June 13, oil prices initially soared, but from three-year lows, and remained well below post-2022 averages. Then, in the immediate aftermath of Trump’s June 23 ceasefire announcement, oil prices retraced much of the war-related run-up. If hostilities continue – always a possibility in the Middle East – there will be significant upside risks to energy and other commodity prices as markets start to worry about Iran’s options for retaliation, which could include disruption of oil production and distribution, as well as of shipping lanes. On balance, the US bombing of Iranian nuclear enrichment facilities on June 21 has injected a new element of uncertainty into an already hyper-volatile world.
至於中東，戰爭的宏觀經濟影響通常透過油價來衡量。以色列於 6 月 13 日對伊朗發動攻擊後，油價最初飆升，但是從三年低點起漲，且仍遠低於 2022 年後的平均水平。隨後，在川普於 6 月 23 日宣布停火後，油價回吐了大部分因戰爭而上漲的幅度。如果敵對行動持續——這在中東始終是可能的——能源及其他大宗商品價格將面臨顯著的上行風險，因市場開始擔憂伊朗的報復選項，可能包括擾亂石油生產與分銷，以及航運通道。綜合來看，美國於 6 月 21 日轟炸伊朗核濃縮設施，為本已極度波動的世界局勢注入了新的不確定因素。
It is far too early to foretell how US entry into Israel’s war against Iran will affect global energy prices. But in one sense, the situation is reminiscent of Saddam Hussein’s invasion of Kuwait in August 1990, which led to a doubling of oil prices within three months. Significantly, the world economy was already slowing toward a 2.5% stall speed in 1991, and the war-related energy shock led to a mild global recession in 1992-93.
現在判斷美國介入以色列對伊朗戰爭將如何影響全球能源價格還為時過早。但在某種意義上，這情況讓人聯想到 1990 年 8 月薩達姆·侯賽因入侵科威特，當時油價在三個月內翻倍。值得注意的是，當時全球經濟已在 1991 年放緩至約 2.5%的停滯速度，而戰爭引發的能源衝擊導致 1992 至 1993 年出現輕微的全球經濟衰退。
The key to the near-term outlook is not US tariffs or the Iran war, but their geopolitical interplay. These shocks have the potential to feed on each other, threatening a vulnerable world economy that is already at risk of stalling out. Cyclical calls are never a sure thing. But this year’s twin shocks make a global recession look increasingly likely.