This paper presents a theory for the maintenance of tropical cyclones through air-sea interaction, challenging the traditional CISK hypothesis. The authors argue that tropical cyclones are maintained by self-induced heat transfer from the ocean, not by preexisting conditional instability. They propose that these storms result from a finite amplitude air-sea interaction instability rather than a linear instability involving ambient potential buoyancy. The study uses idealized models to show that intense, steady-state tropical cyclones can be maintained without ambient conditional instability. In Part II, they demonstrate that weak but finite-amplitude disturbances can intensify in a conditionally neutral environment. The paper discusses the importance of latent and sensible heat flux from the sea surface in tropical cyclone development. It shows that even without sea-air heat flux, some convective available potential energy (CAPE) is present in the initial sounding. The authors emphasize that the maintenance of tropical cyclones is primarily due to self-induced heat transfer from the ocean, not preexisting CAPE. They also highlight the role of cumulus convection in redistributing heat from the sea surface to maintain a neutral environment for slantwise moist convection. The paper presents a steady-state analytical model based on air-sea interaction. It assumes that the thermal and kinematic structure of the tropical cyclone is such that the combined buoyant/centrifugal potential of boundary layer air is zero, indicating neutrality to slantwise moist convection. The model shows that the saturated equivalent potential temperature is uniform along surfaces of constant angular momentum. The study also discusses the relationship between pressure and moist entropy in the boundary layer, showing that the pressure deficit is related to the moist entropy surfeit in the storm center. The paper concludes that the observed absence of tropical cyclone formation when the sea surface temperature is below 26°C is due to the absence of extensive deep conditional instability or neutrality over those parts of the ocean. It also shows that the intensity of tropical cyclones depends directly on sea surface temperature, with higher temperatures leading to more intense storms. The study provides a framework for understanding the dynamics of tropical cyclones through air-sea interaction, emphasizing the role of self-induced heat transfer in their maintenance.This paper presents a theory for the maintenance of tropical cyclones through air-sea interaction, challenging the traditional CISK hypothesis. The authors argue that tropical cyclones are maintained by self-induced heat transfer from the ocean, not by preexisting conditional instability. They propose that these storms result from a finite amplitude air-sea interaction instability rather than a linear instability involving ambient potential buoyancy. The study uses idealized models to show that intense, steady-state tropical cyclones can be maintained without ambient conditional instability. In Part II, they demonstrate that weak but finite-amplitude disturbances can intensify in a conditionally neutral environment. The paper discusses the importance of latent and sensible heat flux from the sea surface in tropical cyclone development. It shows that even without sea-air heat flux, some convective available potential energy (CAPE) is present in the initial sounding. The authors emphasize that the maintenance of tropical cyclones is primarily due to self-induced heat transfer from the ocean, not preexisting CAPE. They also highlight the role of cumulus convection in redistributing heat from the sea surface to maintain a neutral environment for slantwise moist convection. The paper presents a steady-state analytical model based on air-sea interaction. It assumes that the thermal and kinematic structure of the tropical cyclone is such that the combined buoyant/centrifugal potential of boundary layer air is zero, indicating neutrality to slantwise moist convection. The model shows that the saturated equivalent potential temperature is uniform along surfaces of constant angular momentum. The study also discusses the relationship between pressure and moist entropy in the boundary layer, showing that the pressure deficit is related to the moist entropy surfeit in the storm center. The paper concludes that the observed absence of tropical cyclone formation when the sea surface temperature is below 26°C is due to the absence of extensive deep conditional instability or neutrality over those parts of the ocean. It also shows that the intensity of tropical cyclones depends directly on sea surface temperature, with higher temperatures leading to more intense storms. The study provides a framework for understanding the dynamics of tropical cyclones through air-sea interaction, emphasizing the role of self-induced heat transfer in their maintenance.