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In April 2025, the U.S. administration announced a sweeping set of tariffs, ranging from 10% to 60%, on a wide array of imports from China and other manufacturing hubs. Positioned as a strategic move to protect domestic manufacturing and address trade imbalances, these tariffs have triggered global responses that extend far beyond geopolitics, sending aftershocks through international supply chains.
From port operations to production planning, and from freight forwarders to end consumers, every stakeholder now faces a new era of uncertainty. And while global headlines focus on trade wars and diplomatic retaliation, supply chain professionals must focus on something far more urgent: resilience, agility, and cost containment in a rapidly shifting logistics landscape.
A Shifting Global Response
The U.S. tariff policy has prompted swift reactions from trade partners. While some countries have adopted retaliatory tariffs on U.S. goods, others are repositioning themselves as alternative sourcing or transshipment hubs. For instance, countries such as Vietnam, Mexico, Brazil, and Singapore are experiencing increased demand from manufacturers seeking to bypass high-duty routes. Similarly, some governments are lobbying for tariff exemptions or trade concessions to mitigate the blow to their export-dependent economies.
For supply chain professionals, this means dealing with a moving target: evolving regulations, changing trade lanes, and new risk vectors. And the time to act is now.
The Domino Effect on Supply Chains
The immediate impacts of the tariffs have already begun to unfold across major ocean freight corridors:
Increased congestion at East Asian and U.S. ports
East Asian ports, including those in China, Taiwan, and South Korea, have seen a sharp rise in outbound congestion following the tariff announcement. Simultaneously, inbound congestion on the U.S. West Coast has intensified due to a rush of pre-emptive shipments arriving ahead of the tariff hike, straining yard operations and customs processing.
Spike in blank sailings from China to the U.S.
The number of blank sailings between China and the U.S. has increased significantly in the weeks following the April 2025 tariff announcement, further disrupting sailing schedules and reducing available capacity.
- Over 80 blank sailings occurred in April 2025 — the highest since May 2020.
- Container demand dropped 28% (Asia–US West Coast, Week 18) and 42% (Asia–US East Coast, Week 19).
- Trade war uncertainty is causing shippers to pause or cancel shipments, leading to lower vessel utilisation.
- Carriers are responding by cutting capacity and cancelling bookings.
Rerouting and transshipment are causing delays
Some manufacturers are rerouting goods through lower-tariff countries to navigate tariff bands and country-of-origin rules. This strategy adds complexity to customs documentation, prolongs transit times, and increases the risk of delays at intermediate ports.
Rising freight rates due to market disruption
Reduced economies of scale and shifting global demand patterns have contributed to a steady rise in ocean freight rates, impacting overall shipping budgets for manufacturers and freight forwarders.
Increased variability in ETAs
Unpredictable routing and port delays have led to greater fluctuations in estimated time of arrival (ETA), complicating inventory planning and supply chain coordination.
Limited visibility into carrier reliability
Sudden shifts in trade lanes and schedules have made it more difficult for shippers to assess and monitor carrier performance, challenging efforts to maintain service-level agreements and operational efficiency.
What Trends Should We Watch?
Based on these ripple effects, several trends are likely to shape the next quarter:
- Carrier reliability drops on key lanes: Transit time reliability from China to U.S. West Coast ports may decline. This is primarily due to last-minute blank sailings, congestion at origin and destination ports, and customs backlogs.
- Congestion hotspots shift: Ports such as Shanghai, Busan, and Los Angeles are already showing early signs of becoming congestion hotspots. Meanwhile, secondary ports in Vietnam and the Philippines see unusual volume spikes as shippers look for alternative gateways.
- New market dynamics: As U.S. demand contracts due to rising consumer prices, some manufacturers are diversifying into Southeast Asia, the Middle East, and parts of Africa. This could result in the emergence of new east-west and south-south trade corridors over the next year.
- Rise in transshipment activity: This is especially true through tariff-light hubs such as Singapore, the UAE, and Brazil. However, unclear guidelines around country-of-origin documentation may delay customs and increase compliance scrutiny.
What Can Supply Chain Professionals Do?
This is a moment of disruption, but also a window of opportunity for those willing to act decisively. Whether you're a manufacturer or a freight forwarder, the path forward involves striking a balance between agility and intelligence.
Immediate actions:
- Monitor port congestion and blank sailings in real-time to anticipate delays and adjust routing strategies proactively.
- Leverage freight audit automation to manage cost escalations and detect invoicing discrepancies, an often-overlooked drain on margins.
- Invest in predictive visibility tools: In today's volatile environment, having real-time data alone is insufficient. Predictive insights, like those offered by Portcast, help businesses anticipate disruption before it impacts delivery timelines.
Build Resilience, Not Just Redundancy
The tariffs may be political, but their consequences are profoundly operational. Now is the time for supply chain teams to be resilient, proactive, and data-driven. Whether it's mitigating delays, optimising freight costs, or finding new routes to market—Portcast can help.
Contact us today to learn how our predictive visibility solutions can support your business during this volatile time.
