"That Germany was so immensely strong and Austria so dependent upon German strength that the word and will of Germany would at the critical moment be decisive with Austria"

The quote by Edward Grey assesses the characteristics of power and dependency in the relationship in between Germany and Austria-Hungary throughout the early 20th century. At this time, the elaborate web of alliances and the balance of power in Europe were essential in cases leading up to World War I.

Grey's declaration highlights Germany's formidable strength on the European stage, both militarily and politically. Germany, having merged in 1871, became a major power with a strong industrial base and an up-to-date military. This strength offered Germany a dominant impact over its allies, particularly Austria-Hungary, which was less cohesive and struggling with internal ethnic conflicts and political instability.

Austria-Hungary, while still a considerable power, increasingly relied on Germany for support and security. This dependence implied that in crucial matters, particularly those concerning security and foreign policy, Austrian actions were heavily affected by German interests and directives. Grey recommends that any crucial decision made by Austria-- particularly those that may result in conflict or war-- would eventually be swayed or directed by Germany due to this power imbalance.

The implication here is substantial in the context of pre-World War I stress. The assassination of Archduke Franz Ferdinand in 1914, for example, resulted in a crisis where Austria-Hungary sought to take a strong stance against Serbia. Germany's backing was essential for Austria to show confidence, which indicates how Germany's "word and will" were indeed definitive.

In wider terms, Grey's observation underscores the vulnerable nature of alliances when one partner holds considerably more power. It indicates the possible dangers of such reliances, where an effective nation can successfully steer its weaker ally into actions that line up with its own strategic goals, adding to more comprehensive conflicts such as the break out of World War I.