International agreements are known to elicit cooperation based on their stringency, clarity, and enforceability. Yet, it is puzzling that states regularly enter binding and far-reaching agreements whose implications they know little about. Twenty-first century trade faces a major obstacle in non-tariff measures (NTMs), like national product standards, which slow down the flow of goods and raise consumer prices. Still, institutional commitments to dismantling regulatory barriers remain vague, both at the WTO and in preferential trade agreements (PTAs). This paper asks: what allows states to cooperate in the absence of strong and clear rules? I introduce the notion of deferred contracting (DC) to theorize how states can cooperate and make concessions on costly regulatory commitments after treaty ratification so as to avoid domestic vetoes. I argue that a more institutionalized pursuit of DC leads PTA members to converge more in their national product regulations. I introduce a novel dynamic measure of regulatory distance in product standardization built using principal component analysis (PCA), and covering 90 countries between 1995 and 2020. Difference-in-differences estimation with matching reveals that bilateral PTAs with more institutionalized DC fora reduce regulatory distance between members states more than other agreements. Relying on a mixed-method approach, I complement my statistical findings with a case study on the EU-Japan Economic Partnership Agreement (EPA). Existing literature has long established that institutionalized cooperation revolves around visible commitments formalized during politically contested negotiations. This study reveals that, in fact, the politics of treaty implementation is no less fruitful in producing new policy decisions in the shadow of vague and incomplete contracts.

Studies have discussed how international enforcement actions often backfire, prompting violating states to abandon cooperation. Yet we still know little about whether these events can prompt states to cooperate more. We argue that treaty- enforcement episodes exposing clear violations prompt states to strengthen enforcement mechanisms in future agreements, sending a signal that offsets the reputational damage caused by the enforcement action. We test this argument looking at international investment agreements (IIAs) negotiated following investor-state dispute settlement (ISDS) claims, using a PanelMatch difference-in-differences design and a novel dataset of 2,501 IIAs. We find that states accused of directly expropriating investors strengthen ISDS enforcement provisions in subsequent treaties relative to states facing softer allegations or no enforcement. We complement these results with case study on Chile. Our findings reveal that international cooperation can be sustained in the wake of violations, when restoring reputation is better served by stringent commitments than withdrawal.

Why does the EU still lack integration around a common and binding investment screening mechanism (ISM) despite rising global tensions and security concerns? Why is there still significant variation in how EU Member States govern incoming international investment? The literature identifies a political tradeoff for EU governments between attracting FDI and fostering domestic security, shaped by factors like public debt levels, the intensity of R&D in national industries, and the extent of incoming Chinese investment. Yet, we still know little about the role that international institutions play in these government decisions. This paper explores the dense network of bilateral investment treaties (BITs) that individually tie many EU member states to non-EU countries. It argues that being part of BITs with non-EU countries reduces Member States' propensity to introduce ambitious investment screening rules. It finds that a wider network of BITs leads EU Member States to design less comprehensive and stringent ISMs, all else equal. These findings point at an understudied paradox: international institutions like BITs have been designed to foster EU member states’ integration with non-EU economies. At the same time, these agreements limit internal EU integration around a common and binding investment-screening regime. The paper complements explanations for the EU’s lack of a unified ISM that only look at its lagging security integration, pointing at the role of competing economic institutions instead.