Hypersonic Strike Systems of the United States, by South Front.
Even two years ago, hypersonic weapons were barely an item of discussion among the US national security establishment. Today these weapons are all the rage. What accounts for that sudden emergence of US interest in this category of weapons…?
The existing generation of slow missiles are too vulnerable to air defenses:
The triggering reason is most likely the failure of US, French, and British stand-off weapons used against Syria, specifically against targets covered by modern air defenses. Russian and even Soviet-era surface-to-air gun and missile systems racked up an impressive tally of successful interceptions of Tomahawk cruise missiles that still represent the most important component of the US stand-off weapon arsenal. Even the supposedly stealthy cruise missiles like France’s SCALP-EG, Great Britain’s Storm Shadow, and the US JASSM-ER proved to have low survivability against modern defenses. Israel’s equivalent munitions were not an exception to that rule, as they too had to rely on saturation attacks or, more likely, striking targets that were outside the integrated air defense bubble. …
You either go stealth or fast. The West gambled on stealth, but increasingly it looks like hypersonic — the way the Russians went — is a better bet.
Whereas the US military establishment embraced stealth as a “silver bullet” technological solution to all manner of tactical and even strategic problems, Russia’s approach was more measured. While the studies that have led to this conclusion probably will remain classified for a long period of time, the Russian military came to the reasonable conclusion that since avoiding detection cannot be guaranteed, the best way to deal with missile defenses is to decrease exposure time by making the missiles ever-faster.
This trend was already evident during the Cold War, when NATO settled for subsonic anti-ship missiles such as the Exocet, Harpoon, Penguin, Otomat, and ultimately the Tomahawk which had both anti-ship and land-attack applications, which relied on stealth of sorts in the form of flying at extremely low altitudes. USSR, on the other hand, already by the late 1960s was making a major investment in highly supersonic air-, surface- and submarine-launched missiles. By 1980s, Soviet weapons were increasingly employing air-breathing ramjet propulsion which pushed their speeds ever-closer to the hypersonic realm. …
The US recently started down the hypersonic route as well:
Not even the rapid deterioration of Russia-NATO relations in 2014 and later years led to visibly greater interest in these weapons. The Trump Administration’s two rounds of cruise missile strikes against Syria, however, appear to have had that effect. As a result, every service of the US military is interested in the development of at least one weapon system that would provide it with hypervelocity strike capabilities.