10 MPa (100 atn ot 1,450 PSI) to be destroyed by blast from an explosion close to the ground.250 CEP, mAl3r/392 -E;ng La6rl ?age 35 ?0" The development of large nurdbet"s of still more accurate nuclea" weapons, even though their yields nay be rnod.erate o uahes it increasingly rnore difficult toprotect land-based nuclear w€a1lons from an attack, i.e. a first stril(e ainin6 at eliminating these veapons. Even hardened silos may no longer provide sufficientprotection. In consequence, military planners have been and are sti11 searchingfor ner'r counternethods or countersystems that r'Iou].d be safe from attack and maintain "a stable d.eterrencer'. This also involves the fuxther deveJ.opnent of elaborate detection anci identification systems in order to recelve advance warningof an impending attack" This nelr aspect of the nucl-ear arms race wil-I be described in more detail in the folloving paragraphs. 71. Ttre arms controL agreements concluded so far have not, in essence,significantly rest"icted. this Cevelopnent. It is true that the SALT f agleenent betneen the United States and the USSR succeeded in putting a narrov lirnit on the deplopnent of one particular tyFe of countersystem" the so-ca11ed anti-ba1Lis-bic rnissiles (ABx{s) " However, it offered no substantial constraints on the development of meaJrs a].ready devised to penetrate or circumvent an ABM aefence" notably the introduction of l.{IRVs. The possible inportance in this respect of the SAIT II treaty, vhen and if ratified, is treated befow, and. so are the inplications of conceivable limitations on nuclear-weapon testing. 72. There is also an ongoing technical developnent in the fielcl of theatre or tactical nuclear reapons, a-Ithough it has hitherto attTacted less public attention than tha.t in the strategic wea.pons rea1m" T'he thrust of this d.evelopment is" generally speaking, tovards greater flexibility in handJ-ing and. operation. As r'ras indicated in chapter II" this has aheady led to the creation of a plethora of
**Analysis**
The text appears to be discussing the development and deployment of nuclear weapons, the arms race, and the challenges of protecting land-based nuclear weapons from attack. It mentions the development of new technologies and systems to detect and identify potential threats, as well as the ongoing technical development in the field of theatre or tactical nuclear weapons. The text does not seem to be related to any of the economic, social, or cultural aspects, but rather focuses on the military and technological aspects of nuclear weapons.

**Category**
Science and technology, Defense