This is why the workshop had to consider the probable use of nuclear devices if an Earth-threatening object is identified. This is true because nuclear devices yield tens of millions times more energy per kilogram of payload, and very large energies are required to perturb massive NEOs significantly, even when the required velocity change to miss the Earth may be only a few inches per second. In summary, workshop participants concluded that any defensive planning for a potential impact should include nuclear technology. Clearly, any such use of nuclear devices would require appropriate national policy as well as international agreements and protocols. Such integrated systems do not currently exist and would require considerable development.
Early warning is the ultimate key to success.
Both ground and space-based assets should be considered. Nuclear explosives would be essential to deflect a large object within the foreseeable future. More benign in-situ methods may become feasible as manned space activities mature and expand.